A325432 Complement of A325431.

3, 4, 6, 8, 15, 20, 21, 27, 28, 30, 33, 36, 39, 40, 42, 44, 48, 51, 52, 54, 56, 57, 64, 66, 68, 69, 72, 75, 76, 78, 87, 88, 92, 93, 96, 100, 102, 104, 105, 111, 114, 116, 123, 124, 128, 129, 135, 136, 138, 140, 141, 147, 148, 150, 152, 159, 164, 165, 172

Offset: 1

Author

Clark Kimberling, May 01 2019

Keywords

• nonn
• easy

Comments

These are the numbers 3x and 4x as x ranges through the numbers x > 1 in A325431.

Equivalently, numbers k whose exponent of the highest power of 3 dividing k and exponent of the highest power of 4 dividing k have an opposite parity. The asymptotic density of this sequence is 7/20. - Amiram Eldar, Sep 20 2020

Links

• Clark Kimberling, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A325417, A325431.

Programs

Mathematica

a = {1}; Do[AppendTo[a, NestWhile[# + 1 &, Last[a] + 1, Apply[Or,
Map[MemberQ[a, #] &, Select[Flatten[{#/3, #/4}],
IntegerQ]]] &]], {150}]; a          (* A325431 *)
Complement[Range[Last[a]], a]       (* A325432 *)
(* Peter J. C. Moses, Apr 25 2019 *)
Select[Range[100], !Equal @@ Mod[IntegerExponent[#, {3, 4}], 2] &] (* Amiram Eldar, Sep 20 2020 *)