Data update

Task/Arithmetic-numbers/Pluto/arithmetic-numbers.pluto

@@ -0,0 +1,34 @@
+local int = require "int"
+local fmt = require "fmt"
+require "table2"
+
+local arithmetic = {1}
+local primes = {}
+local limit = 1e6
+local n = 3
+while #arithmetic < limit do
+    local divs = int.divisors(n)
+    if #divs == 2 then
+        primes:insert(n)
+        arithmetic:insert(n)
+    else
+        local mean = divs:mean()
+        if mean % 1 == 0 then arithmetic:insert(n) end
+    end
+    n += 1
+end
+print("The first 100 arithmetic numbers are:")
+fmt.tprint("%3d", arithmetic:slice(1, 100), 10)
+
+for {1e3, 1e4, 1e5, 1e6} as x do
+    local last = arithmetic[x]
+    fmt.print("\nThe %,sth arithmetic number is: %,s", x, last)
+    local pcount = primes:findindex(|p| -> p >= last, 1, true)
+    if !pcount then
+        pcount = #primes
+    elseif !int.isprime(last) then
+        pcount -= 1;
+    end
+    local comp = x - pcount - 1  -- 1 is not composite
+    fmt.print("The count of such numbers <= %,s which are composite is %,s.", last, comp)
+end