A178646 a(n) = product of divisors d of n such that d^k is not equal to n for any k >= 1.
1, 1, 1, 1, 1, 6, 1, 4, 1, 10, 1, 144, 1, 14, 15, 8, 1, 324, 1, 400, 21, 22, 1, 13824, 1, 26, 9, 784, 1, 27000, 1, 512, 33, 34, 35, 46656, 1, 38, 39, 64000, 1, 74088, 1, 1936, 2025, 46, 1, 5308416, 1, 2500
Offset: 1
Keywords
Examples
For n = 16, set of such divisors is {1, 8}; a(16) = 1*8=8.
Programs
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Sage
A178646 = lambda n: prod(d for d in divisors(n) if not n.is_power_of(d)) # D. S. McNeil, Dec 28 2010