A287559 Positions of 2 in A287556.

4, 7, 9, 14, 19, 21, 26, 32, 34, 40, 43, 45, 49, 54, 60, 63, 67, 69, 74, 80, 82, 88, 91, 93, 97, 102, 108, 111, 116, 119, 121, 126, 129, 134, 140, 143, 148, 151, 153, 158, 163, 165, 170, 176, 178, 184, 187, 189, 194, 200, 203, 205, 209, 214, 220, 223, 228

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 0, 1, 3, 2, 1, 3, 2, 0, 2, 0, 1, 3, 3, 2, 0, 1, 1, 3, 2, 0, with

0 in positions given by A287557,

1 in positions given by A287558,

2 in positions given by A287560,

3 in positions given by A287559.

Links

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

Crossrefs

Cf. A287556, A287557, A287558, A287560.

Programs

Mathematica

s = Nest[Flatten[# /. {0 -> {0, 1, 3, 2}, 1 -> {1, 3, 2, 0}, 2 -> {3, 2, 0, 1}, 3 -> {2, 0, 1, 3}}] &, {0}, 9];   (* A287556 *)
Flatten[Position[s, 0]]; (* A287557 *)
Flatten[Position[s, 1]]; (* A287558 *)
Flatten[Position[s, 2]]; (* A287559 *)
Flatten[Position[s, 3]]; (* A287560 *)