A325464 a(n) is the least number not 2*a(m) or 3*a(m)-2 for any m < n.

1, 3, 4, 5, 9, 11, 12, 14, 15, 16, 17, 19, 20, 21, 23, 26, 27, 29, 33, 35, 36, 37, 39, 41, 44, 45, 47, 48, 50, 51, 53, 56, 57, 59, 60, 62, 63, 64, 65, 68, 69, 71, 73, 75, 77, 80, 81, 83, 84, 86, 87, 89, 91, 92, 93, 95, 98, 99, 101, 104, 105, 107, 108, 110

Offset

1,2

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 number 2 is disallowed, so that a(2) = 3, whence the numbers 6 and 7 are disallowed, and a(3) = 4.  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[{#/2, (#+2)/3}],
IntegerQ]]] &]], {150}]; a          (* A325464 *)
Complement[Range[Last[a]], a]       (* A325465 *)
(* Peter J. C. Moses, Apr 25 2019 *)

Crossrefs

Cf. A325417, A325465.

Sequence in context: A295718 A035236 A047600 * A010384 A028954 A035247

Adjacent sequences: A325461 A325462 A325463 * A325465 A325466 A325467

Keyword

nonn,easy

Author

Clark Kimberling, May 01 2019

Status

approved