A287436 Positions of 1 in A053838.

2, 4, 9, 10, 15, 17, 21, 23, 25, 28, 33, 35, 39, 41, 43, 47, 49, 54, 57, 59, 61, 65, 67, 72, 73, 78, 80, 82, 87, 89, 93, 95, 97, 101, 103, 108, 111, 113, 115, 119, 121, 126, 127, 132, 134, 137, 139, 144, 145, 150, 152, 156, 158, 160, 165, 167, 169, 173, 175

Offset: 1

Author

Clark Kimberling, May 26 2017

Keywords

• nonn
• easy

Comments

The definition refers to a different offset in A053838.

a(n) - a(n-1) is in {1,2,3,4,5} for n >= 1; also, 3n - a(n) is in {0, 1, 2} for n >= 1. The first 20 numbers 3n - a(n) are 1, 2, 0, 2, 0, 1, 0, 1, 2, 2, 0, 1, 0, 1, 2, 1, 2, 0, 0, 1, with 0 in positions given by A287437.

Does this differ from A026602? - R. J. Mathar, Jun 14 2017

Links

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

Crossrefs

Cf. A053838, A287435, A287437.

Programs

Mathematica

s = Nest[Flatten[# /. {0->{0, 1, 2}, 1->{1, 2, 0}, 2->{2, 0, 1}}] &, {0}, 9]; (* A053838 *)
Flatten[Position[s, 0]]; (* A287435 *)
Flatten[Position[s, 1]]; (* A287436 *)
Flatten[Position[s, 2]]; (* A287437 *)