Data update

Task/Untouchable-numbers/Python/untouchable-numbers.py

@@ -0,0 +1,93 @@
+def prime_sieve(limit: int):
+    p = 3
+
+    limit += 1
+
+    c = [False] * limit
+
+    c[0] = True
+    c[1] = True
+
+    for i in range(4, limit, 2):
+        c[i] = True
+
+    while True:
+        p2 = p * p
+
+        if p2 >= limit:
+            break
+
+        for i in range(p2, limit, 2 * p):
+            c[i] = True
+
+        while True:
+            p += 2
+
+            if not c[p]:
+                break
+
+    return c
+
+def main():
+    limit = 1000000
+
+    uc = 2
+    p = 10
+    m = 63
+    ul = 151000
+
+    c = prime_sieve(limit)
+    n = m * limit + 1
+
+    sum_divs = [0] * n
+
+    for i in range(1, n):
+        for j in range(i, n, i):
+            sum_divs[j] += i
+
+    s = [False] * n
+
+    for i in range(1, n):
+        sumation = sum_divs[i] - i
+        if sumation <= n:
+            s[sumation] = True
+
+    untouchable = [0] * ul
+
+    untouchable[0] = 2
+    untouchable[1] = 5
+
+    for n in range(6, limit+1, 2):
+        if not s[n] and c[n - 1] and c[n-3]:
+            untouchable[uc] = n
+            uc += 1
+
+    print("List of untouchable numbers <= 2,000:")
+
+    for i in range(uc):
+        j = untouchable[i]
+
+        if j > 2000:
+            break
+
+        print("%3d " % j, end=' ')
+
+        if not ((i+1) % 10):
+            print()
+
+    print("\n\n%d untouchable numbers were found  <=     2,000\n" % i)
+
+    for i in range(uc):
+        j = untouchable[i]
+
+        if j > p:
+            print("%d untouchable numbers were found  <= %d\n" % (i, p))
+            p *= 10
+
+            if p == limit:
+                break
+
+    print("%d untouchable numbers were found  <= %d" % (uc, limit))
+
+if __name__ == '__main__':
+    main()