OFFSET
1,2
COMMENTS
Equivalently, numbers k whose exponent of the highest power of 3 dividing k and exponent of the highest power of 4 dividing k have the same parity. The asymptotic density of this sequence is 13/20. - Amiram Eldar, Sep 20 2020
LINKS
Clark Kimberling, Table of n, a(n) for n = 1..10000
EXAMPLE
The sequence necessarily starts with 1. The next 2 terms are determined as follows: because a(1) = 1, the numbers 3 and 4 are disallowed, so that a(2) = 2, whence the numbers 6 and 8 are disallowed, and a(3) = 5. See A325417 for a guide to related sequences.
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
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, May 01 2019
STATUS
approved