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

1,1

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

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 *)

Crossrefs

Cf. A325417, A325431.

Sequence in context: A340770 A242870 A025073 * A204659 A134580 A007749

Adjacent sequences: A325429 A325430 A325431 * A325433 A325434 A325435

Keyword

nonn,easy

Author

Clark Kimberling, May 01 2019

Status

approved