A287409 Positions of 1 in A287407.

2, 5, 9, 12, 14, 17, 21, 23, 26, 30, 32, 35, 39, 41, 44, 47, 50, 54, 57, 59, 62, 65, 68, 72, 75, 77, 80, 84, 86, 89, 92, 95, 99, 102, 104, 107, 111, 113, 116, 120, 122, 125, 128, 131, 135, 137, 140, 144, 147, 149, 152, 156, 158, 161, 165, 167, 170, 173, 176

Offset: 1

Author

Clark Kimberling, May 25 2017

Keywords

• nonn
• easy

Comments

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, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, with 0 in positions given by A287410.

Links

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

Crossrefs

Cf. A287407, A287408, A287410.

Programs

Mathematica

s = Nest[Flatten[# /. {0->{0, 1, 2}, 1->{2, 1, 0}, 2->{2, 0, 1}}] &, {0}, 9]; (*A287407*)
Flatten[Position[s, 0]]; (*A287408*)
Flatten[Position[s, 1]]; (*A287409*)
Flatten[Position[s, 2]]; (*A287410*)