A287575 Positions of 3 in A287571.

2, 7, 9, 16, 20, 22, 27, 29, 35, 37, 44, 46, 49, 56, 58, 63, 65, 72, 74, 79, 82, 87, 89, 96, 100, 102, 107, 109, 115, 117, 124, 126, 132, 134, 139, 141, 147, 149, 156, 158, 161, 168, 170, 175, 178, 183, 185, 192, 195, 197, 204, 206, 209, 216, 218, 223, 226

Offset: 1

Author

Clark Kimberling, Jun 01 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 2, 1, 3, 0, 0, 2, 1, 3, 1, 3, 0, 2, 3, 0, 2, 1, 3, 0, 2, 1, with

0 in positions given by A287574,

1 in positions given by A287575,

2 in positions given by A287572,

3 in positions given by A287573.

Links

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

Crossrefs

Cf. A287571, A287572, A287573, A287574.

Programs

Mathematica

s = Nest[Flatten[# /. {0 -> {0,3,1,2}, 1 -> {3,1,2,0}, 2 -> {1,2,0,3}, 3 -> {2,0,3,1}}] &, {0}, 9];   (* A287571 *)
Flatten[Position[s, 0]]; (* A287572 *)
Flatten[Position[s, 1]]; (* A287573 *)
Flatten[Position[s, 2]]; (* A287574 *)
Flatten[Position[s, 3]]; (* A287575 *)