A325444 Difference sequence of A325417.

2, 2, 2, 1, 1, 2, 1, 1, 2, 2, 2, 1, 1, 2, 4, 2, 2, 1, 1, 2, 1, 3, 2, 2, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 2, 1, 3, 2, 2, 1, 1, 2, 2, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 2, 2, 2, 1, 1, 2, 4, 2, 2, 1, 1, 2, 1, 3, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 1, 3, 2, 2, 1

Offset: 1

Author

Clark Kimberling, May 03 2019

Keywords

• nonn
• easy

Comments

See A325417 for a guide to related sequences. Conjecture: all the differences are in {1,2,3,4}; a count of differences d(n) = a(n)-a(n-1) for n=2..10000 follows: 4755 occurrences of d(n) = 1; 4332 of 2; 744 of 3; and 169 of 4.

Examples

			A325417 is given by A(n) = least number not 2*A(m) or 3*A(m)+1 for any m < n, so that A = (1,3,5,7,8,9,11, ...), with differences (2,2,2,1,1,2,...).
		

Links

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

Crossrefs

Cf. A325417, A325445.

Programs

Mathematica

a = {1}; Do[AppendTo[a, NestWhile[# + 1 &, Last[a] + 1,
Apply[Or, Map[MemberQ[a, #] &, Select[Flatten[{#/2, (# - 1)/3}],
IntegerQ]]] &]], {2000}]; a ;       (* A325417 *)
c = Complement[Range[Last[a]], a] ; (* A325418 *)
Differences[a]  (* A325444 *)
Differences[c]  (* A325445 *)
(* Peter J. C. Moses, Apr 23 2019 *)