A325521 Difference sequence of A325428.

2, 1, 3, 1, 2, 3, 1, 1, 2, 2, 2, 4, 2, 1, 3, 3, 1, 2, 2, 1, 3, 1, 2, 1, 2, 1, 1, 4, 3, 3, 1, 1, 1, 3, 1, 1, 4, 2, 4, 1, 2, 3, 1, 1, 2, 2, 2, 5, 1, 1, 6, 1, 2, 2, 1, 3, 1, 1, 1, 3, 1, 1, 2, 2, 6, 2, 1, 3, 3, 1, 2, 1, 1, 4, 1, 2, 1, 2, 1, 1, 4, 2, 1, 3, 1, 1

Offset: 1

Author

Clark Kimberling, May 06 2019

Keywords

• nonn
• easy

Examples

			See A325417 for a guide to related sequences. Conjecture: every term is in {1,2,3,4,5,6,7,8,9}.
		

Links

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

Crossrefs

Cf. A325417, A325428, A325520.

Programs

Mathematica

a = {1}; Do[AppendTo[a, NestWhile[# + 1 &, Last[a] + 1, Apply[Or,
Map[MemberQ[a, #] &, Select[Flatten[{(# - 1)/2,
If[Mod[#, 3] == 0, (2 #)/3, 0] + If[Mod[#, 3] == 1, 1/3 (1 + 2 #), 0]}],
IntegerQ || # == 0]]] &]], {200}]; a ; (* A325427 *)
c = Complement[Range[Last[a]], a] ;    (* A325428 *)
Differences[a]  (* A325520 *)
Differences[c]  (* A325521 *)
(* Peter J. C. Moses, Apr 23 2019 *)