A287580 Positions of 3 in A287576.

2, 7, 12, 13, 17, 22, 27, 32, 36, 37, 42, 47, 51, 56, 57, 62, 67, 72, 73, 78, 82, 87, 92, 93, 97, 102, 107, 112, 116, 117, 122, 127, 132, 133, 138, 143, 147, 152, 153, 158, 162, 167, 172, 173, 177, 182, 187, 192, 193, 198, 203, 208, 212, 213, 218, 223, 227

Offset: 1

Author

Clark Kimberling, Jun 01 2017

Keywords

• nonn
• easy

Comments

a(n) - a(n-1) is in {1,4,5} 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, 0, 3, 3, 2, 1, 0, 0, 3, 2, 1, 1, 0, 3, 2, 1, 0, 3, 2, with

0 in positions given by A287579,

1 in positions given by A287580,

2 in positions given by A287577,

3 in positions given by A287578.

Links

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

Crossrefs

Cf. A287576, A287577, A287578, A287579.

Programs

Mathematica

s = Nest[Flatten[# /. {0 -> {0,3,2,1}, 1 -> {3,2,1,0}, 2 -> {2,1,0,3}, 3 -> {1,0,3,2}}] &, {0}, 9];   (* A287576 *)
Flatten[Position[s, 0]]; (* A287577 *)
Flatten[Position[s, 1]]; (* A287578 *)
Flatten[Position[s, 2]]; (* A287579 *)
Flatten[Position[s, 3]]; (* A287580 *)

Formula

a(n) = 4n - A287576(n) for n >= 1.