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1045 changed files with 18889 additions and 2777 deletions
70
Task/Blum-integer/Mathematica/blum-integer.math
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70
Task/Blum-integer/Mathematica/blum-integer.math
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ClearAll[BlumIntegerQ, BlumIntegersInRange, PrimePi2, BlumCount, binarySearch, BlumInts, timing, upperLimitEstimate, lastDigit, lastDigitDistributionPercents];
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BlumIntegerQ[n_Integer] := With[{factors = FactorInteger[n]},
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n ~ Mod ~ 4 == 1 &&
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Length[factors] == 2 &&
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factors[[1, 1]] ~ Mod ~ 4 == 3 &&
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Last@Total@factors == 2
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];
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SetAttributes[BlumIntegerQ, Listable];
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BlumIntegersInRange[n_Integer] := BlumIntegersInRange[1, n];
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BlumIntegersInRange[start_Integer, end_Integer] :=
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Select[Range[start + (4 - start) ~ Mod ~ 4, end, 4] + 1, BlumIntegerQ];
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(* Counts semiprimes. See https://people.maths.ox.ac.uk/erban/papers/paperDCRE.pdf *)
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PrimePi2[x_] := (PrimePi[Sqrt[x]] - PrimePi[Sqrt[x]]^2)/2 + Sum[PrimePi[x/Prime[p]], {p, 1, PrimePi[Sqrt[x]]}];
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SetAttributes[PrimePi2, Listable];
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(* Blum integers are semiprimes that are 1 mod 4, with two distinct factors where both factors are 3 mod 4. The following function gives an approximation of the number of Blum integers <= x.
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According to my tests, this function tends to overestimate by approximately 5% in the range we're interested in.
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*)
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BlumCount[x_] := Ceiling[(PrimePi2[x] - PrimePi[Sqrt[x]]) / 4];
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SetAttributes[BlumCount, Listable];
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binarySearch[f_, targetValue_] :=
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Module[{lo = 1, mid, hi = 1, currentValue},
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While[f[hi] < targetValue,
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hi *= 2;];
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While[lo <= hi,
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mid = Ceiling[(lo + hi) / 2];
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currentValue = f[mid];
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If[currentValue < targetValue,
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lo = mid + 1;];
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If[currentValue > targetValue,
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hi = mid - 1;];
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If[currentValue == targetValue,
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While[f[mid] == targetValue,
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mid++;
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];
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Return[mid - 1];
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];
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];
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];
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lastDigit[n_Integer] := n ~ Mod ~ 10;
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SetAttributes[lastDigit, Listable];
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upperLimitEstimate = Ceiling[binarySearch[BlumCount, 400000]* 1.1];
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timing = First@AbsoluteTiming[BlumInts = BlumIntegersInRange[upperLimitEstimate];];
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lastDigitDistributionPercents = N[Counts@lastDigit@BlumInts[[;; 400000]] / 4000, 5];
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Print["Calculated the first ", Length[BlumInts],
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" Blum integers in ", timing, " seconds."];
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Print[];
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Print["First 50 Blum integers:"];
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Print[TableForm[Partition[BlumInts[[;; 50]], 10],
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TableAlignments -> Right]];
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Print[];
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Print[Grid[
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Table[{"The ", n , "th Blum integer is: ",
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BlumInts[[n]]}, {n, {26828, 100000, 200000, 300000, 400000}}] ,
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Alignment -> Right]]
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Print[];
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Print["% distribution of the first 400,000 Blum integers:"];
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Print[Grid[
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Table[{lastDigitDistributionPercents[n], "% end in ",
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n}, {n, {1, 3, 7, 9}} ], Alignment -> Right]];
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@ -1,59 +1,57 @@
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(phixonline)-->
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<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
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<span style="color: #008080;">constant</span> <span style="color: #000000;">LIMIT</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1e7</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">N</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">((</span><span style="color: #7060A8;">floor</span><span style="color: #0000FF;">(</span><span style="color: #000000;">LIMIT</span><span style="color: #0000FF;">/</span><span style="color: #000000;">3</span><span style="color: #0000FF;">)-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)/</span><span style="color: #000000;">4</span><span style="color: #0000FF;">)+</span><span style="color: #000000;">1</span>
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with javascript_semantics
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constant LIMIT = 1e7, N = floor((floor(LIMIT/3)-1)/4)+1
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<span style="color: #008080;">function</span> <span style="color: #000000;">Sieve4n_3_Primes</span><span style="color: #0000FF;">()</span>
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<span style="color: #004080;">sequence</span> <span style="color: #000000;">sieve</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">N</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">p4n3</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
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<span style="color: #008080;">for</span> <span style="color: #000000;">idx</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">N</span> <span style="color: #008080;">do</span>
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<span style="color: #008080;">if</span> <span style="color: #000000;">sieve</span><span style="color: #0000FF;">[</span><span style="color: #000000;">idx</span><span style="color: #0000FF;">]=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
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<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">idx</span><span style="color: #0000FF;">*</span><span style="color: #000000;">4</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span>
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<span style="color: #000000;">p4n3</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">n</span>
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<span style="color: #008080;">if</span> <span style="color: #000000;">idx</span><span style="color: #0000FF;">+</span><span style="color: #000000;">n</span><span style="color: #0000FF;">></span><span style="color: #000000;">N</span> <span style="color: #008080;">then</span>
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<span style="color: #000080;font-style:italic;">// collect the rest</span>
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<span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">idx</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">N</span> <span style="color: #008080;">do</span>
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<span style="color: #008080;">if</span> <span style="color: #000000;">sieve</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
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<span style="color: #000000;">p4n3</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">4</span><span style="color: #0000FF;">*</span><span style="color: #000000;">j</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
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<span style="color: #008080;">exit</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
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<span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">idx</span><span style="color: #0000FF;">+</span><span style="color: #000000;">n</span> <span style="color: #008080;">to</span> <span style="color: #000000;">N</span> <span style="color: #008080;">by</span> <span style="color: #000000;">n</span> <span style="color: #008080;">do</span>
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<span style="color: #000000;">sieve</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
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<span style="color: #008080;">return</span> <span style="color: #000000;">p4n3</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
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function Sieve4n_3_Primes()
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sequence sieve = repeat(0,N), p4n3 = {}
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for idx=1 to N do
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if sieve[idx]=0 then
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integer n = idx*4-1
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p4n3 &= n
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if idx+n>N then
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// collect the rest
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for j=idx+1 to N do
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if sieve[j]=0 then
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p4n3 &= 4*j-1
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end if
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end for
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exit
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end if
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for j=idx+n to N by n do
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sieve[j] = 1
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end for
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end if
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end for
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return p4n3
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end function
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<span style="color: #004080;">sequence</span> <span style="color: #000000;">p4n3</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">Sieve4n_3_Primes</span><span style="color: #0000FF;">(),</span>
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<span style="color: #000000;">BlumField</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #004600;">false</span><span style="color: #0000FF;">,</span><span style="color: #000000;">LIMIT</span><span style="color: #0000FF;">),</span>
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<span style="color: #000000;">Blum50</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{},</span> <span style="color: #000000;">counts</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">10</span><span style="color: #0000FF;">)</span>
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sequence p4n3 = Sieve4n_3_Primes(),
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BlumField = repeat(false,LIMIT),
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Blum50 = {}, counts = repeat(0,10)
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<span style="color: #008080;">for</span> <span style="color: #000000;">idx</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span> <span style="color: #008080;">in</span> <span style="color: #000000;">p4n3</span> <span style="color: #008080;">do</span>
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<span style="color: #008080;">for</span> <span style="color: #000000;">bj</span> <span style="color: #008080;">in</span> <span style="color: #000000;">p4n3</span> <span style="color: #008080;">from</span> <span style="color: #000000;">idx</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span> <span style="color: #008080;">do</span>
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<span style="color: #004080;">atom</span> <span style="color: #000000;">k</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">*</span><span style="color: #000000;">bj</span>
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<span style="color: #008080;">if</span> <span style="color: #000000;">k</span><span style="color: #0000FF;">></span><span style="color: #000000;">LIMIT</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
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<span style="color: #000000;">BlumField</span><span style="color: #0000FF;">[</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #004600;">true</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
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<span style="color: #004080;">integer</span> <span style="color: #000000;">count</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
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<span style="color: #008080;">for</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">,</span><span style="color: #000000;">k</span> <span style="color: #008080;">in</span> <span style="color: #000000;">BlumField</span> <span style="color: #008080;">do</span>
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<span style="color: #008080;">if</span> <span style="color: #000000;">k</span> <span style="color: #008080;">then</span>
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<span style="color: #008080;">if</span> <span style="color: #000000;">count</span><span style="color: #0000FF;"><</span><span style="color: #000000;">50</span> <span style="color: #008080;">then</span> <span style="color: #000000;">Blum50</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">n</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
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<span style="color: #000000;">counts</span><span style="color: #0000FF;">[</span><span style="color: #7060A8;">remainder</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">,</span><span style="color: #000000;">10</span><span style="color: #0000FF;">)]</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
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<span style="color: #000000;">count</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
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<span style="color: #008080;">if</span> <span style="color: #000000;">count</span><span style="color: #0000FF;">=</span><span style="color: #000000;">50</span> <span style="color: #008080;">then</span>
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<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"First 50 Blum integers:\n%s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #7060A8;">join_by</span><span style="color: #0000FF;">(</span><span style="color: #000000;">Blum50</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">10</span><span style="color: #0000FF;">,</span><span style="color: #008000;">" "</span><span style="color: #0000FF;">,</span><span style="color: #000000;">fmt</span><span style="color: #0000FF;">:=</span><span style="color: #008000;">"%3d"</span><span style="color: #0000FF;">)})</span>
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<span style="color: #008080;">elsif</span> <span style="color: #000000;">count</span><span style="color: #0000FF;">=</span><span style="color: #000000;">26828</span> <span style="color: #008080;">or</span> <span style="color: #7060A8;">remainder</span><span style="color: #0000FF;">(</span><span style="color: #000000;">count</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1e5</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
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<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"The %,7d%s Blum integer is: %,9d\n"</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">count</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">ord</span><span style="color: #0000FF;">(</span><span style="color: #000000;">count</span><span style="color: #0000FF;">),</span><span style="color: #000000;">n</span><span style="color: #0000FF;">})</span>
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<span style="color: #008080;">if</span> <span style="color: #000000;">count</span><span style="color: #0000FF;">=</span><span style="color: #000000;">4e5</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
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<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\nPercentage distribution of the first 400,000 Blum integers:\n"</span><span style="color: #0000FF;">)</span>
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<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span> <span style="color: #008080;">in</span> <span style="color: #000000;">counts</span> <span style="color: #008080;">do</span>
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<span style="color: #008080;">if</span> <span style="color: #000000;">n</span> <span style="color: #008080;">then</span>
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<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">" %6.3f%% end in %d\n"</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">n</span><span style="color: #0000FF;">/</span><span style="color: #000000;">4000</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">})</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
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<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
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<!--
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for idx,n in p4n3 do
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for bj in p4n3 from idx+1 do
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atom k = n*bj
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if k>LIMIT then exit end if
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BlumField[k] = true
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end for
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end for
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integer count = 0
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for n,k in BlumField do
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if k then
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if count<50 then Blum50 &= n end if
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counts[remainder(n,10)] += 1
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count += 1
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if count=50 then
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printf(1,"First 50 Blum integers:\n%s\n",{join_by(Blum50,1,10," ",fmt:="%3d")})
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elsif count=26828 or remainder(count,1e5)=0 then
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printf(1,"The %,7d%s Blum integer is: %,9d\n", {count,ord(count),n})
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if count=4e5 then exit end if
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end if
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end if
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end for
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printf(1,"\nPercentage distribution of the first 400,000 Blum integers:\n")
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for i,n in counts do
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if n then
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printf(1," %6.3f%% end in %d\n", {n/4000, i})
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end if
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end for
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