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

1,1

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

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 *)

Crossrefs

Cf. A325417, A325444.

Sequence in context: A097860 A098979 A071928 * A165207 A130501 A049116

Adjacent sequences: A325442 A325443 A325444 * A325446 A325447 A325448

Keyword

nonn,easy

Author

Clark Kimberling, May 03 2019

Status

approved