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.

A362594 Exponentially odd numbers that are neither squarefree nor prime powers.

Original entry on oeis.org

24, 40, 54, 56, 88, 96, 104, 120, 135, 136, 152, 160, 168, 184, 189, 216, 224, 232, 248, 250, 264, 270, 280, 296, 297, 312, 328, 344, 351, 352, 375, 376, 378, 384, 408, 416, 424, 440, 456, 459, 472, 480, 486, 488, 513, 520, 536, 544, 552, 568, 584, 594, 608, 616
Offset: 1

Views

Author

Michael De Vlieger, Sep 08 2023

Keywords

Comments

The asymptotic density of this sequence is A065463 - A059956 = 0.09651509914... . - Amiram Eldar, Sep 27 2023

Examples

			24 = 2^3 * 3^1 is in this sequence because it has 2 distinct prime factors whose multiplicities are odd and one such multiplicity exceeds 1.
		

Crossrefs

Programs

  • Mathematica
    Select[Select[Range[1000], Nor[SquareFreeQ[#], PrimePowerQ[#]] &], Times @@ FactorInteger[#][[All, 1]] == (Sqrt[#] /. (c_ : 1)*a_^(b_ : 0) :> (c*a^b)^2) &]

Formula

This sequence is A126706 INTERSECT A268335.
A268335 = Union(S, T) where S is this sequence and T = {A005117 U A097054} = {A005117 U A246551}.