Print the nth Sphenic Number

A Sphenic number is a product of 3 distinct primes.

Author: gunslingster

Sphenic Numbers/sphenic_numbers.py

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+import math
+
+def primes(n):
+    sieve = [True] * n
+    for i in range(3, int(n**0.5) + 1, 2):
+        if sieve[i]:
+            for j in range(2*i, n, i):
+                sieve[j] = False
+    return [2] + [i for i in range(3, n, 2) if sieve[i]]
+
+def isSpehnic(num):
+    p = primes(num)
+    # The very smallest combiantion of primes would contain 2 and 3
+    # We only need to check numbers <= num/6
+    p = [n for n in p if n <= num//6]
+    l = len(p)
+    for i in range(l - 2):
+        for j in range(i+1, l-1):
+            for k in range(j+1, l):
+                if p[i] * p[j] * p[k] == num:
+                    return True
+    return False
+
+def main():
+    n = int(input('Enter n: '))
+    count = -1
+    curr = 0
+    while count < n:
+        curr += 1
+        if isSpehnic(curr):
+            count += 1
+    print(curr)
+
+main()