A287554 Positions of 2 in A053839.

3, 6, 9, 16, 18, 21, 28, 31, 33, 40, 43, 46, 52, 55, 58, 61, 66, 69, 76, 79, 81, 88, 91, 94, 100, 103, 106, 109, 115, 118, 121, 128, 129, 136, 139, 142, 148, 151, 154, 157, 163, 166, 169, 176, 178, 181, 188, 191, 196, 199, 202, 205, 211, 214, 217, 224, 226

Offset: 1

Author

Clark Kimberling, May 31 2017

Keywords

• nonn
• easy

Comments

a(n) - a(n-1) is in {1,2,3,4,5,6,7} for n >= 1; also, 4n - a(n) is in {0,1,2,3} for n >= 1. The first 20 numbers 4n - a(n) are 1, 2, 3, 0, 2, 3, 0, 1, 3, 0, 1, 2, 0, 1, 2, 3, 2, 3, 0, 1, with

0 in positions given by A287555,

1 in positions given by A287552,

2 in positions given by A287553,

3 in positions given by A287554.

Links

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

Crossrefs

Cf. A053839, A287552, A287553, A287555.

Programs

Mathematica

s = Nest[Flatten[# /. {0 -> {0, 1, 2, 3}, 1 -> {1, 2, 3, 0}, 2 -> {2, 3, 0, 1}, 3 -> {3, 0, 1, 2}}] &, {0}, 9];  (* A053839 *)
Flatten[Position[s, 0]]; (* A287552 *)
Flatten[Position[s, 1]]; (* A287553 *)
Flatten[Position[s, 2]]; (* A287554 *)
Flatten[Position[s, 3]]; (* A287555 *)