A325445 Difference sequence of A325418.

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

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 {1,2,3,4,6}; 5 does not occur; a count of differences d(n) = a(n)-a(n-1) for n=2..10000 follows: 1082 occurrences of d(n) = 1; 2693 of 2; 744 of 3; 1609 of 4, 0 of 5, and 198 of 6.

Links

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

Crossrefs

Cf. A325417, A325444.

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 *)