cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A175084 Possible values for product of perfect divisors of n.

Original entry on oeis.org

1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 28, 29, 30, 31, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78
Offset: 1

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Author

Jaroslav Krizek, Jan 24 2010

Keywords

Comments

Perfect divisor of n is divisor d such that d^k = n for some k >= 1. All terms of this sequence occur only once. See A089723 (number of perfect divisors of n) and A175068 (product of perfect divisors of n).
Complement of A175085. - Jaroslav Krizek, Jan 30 2010

Crossrefs

Cf. A175087 (characteristic function).

Programs

  • Mathematica
    With[{nn = 78}, TakeWhile[#, # <= nn &] &@ Union@ Table[Apply[Times, Select[Divisors@ n, Or[# == 1, #^IntegerExponent[n, #] == n] &]], {n, nn}] ] (* Michael De Vlieger, Nov 21 2017 *)