A287387 Positions of 1 in A287385.

2, 5, 9, 12, 14, 17, 20, 24, 26, 29, 33, 35, 39, 41, 44, 47, 50, 54, 56, 59, 63, 65, 69, 71, 75, 77, 80, 83, 86, 90, 92, 96, 98, 102, 104, 107, 110, 114, 116, 120, 122, 125, 128, 131, 135, 137, 140, 144, 147, 149, 152, 155, 159, 161, 164, 167, 171, 174, 176

Offset: 1

Author

Clark Kimberling, May 25 2017

Keywords

• nonn
• easy

Comments

a(n) - a(n-1) is in {2,3,4} for n >= 1; also, 3n - a(n) is in {0,1} for n >= 1. The first 20 numbers 3n - a(n) are 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 1, with 0 in positions given by A287388.

Links

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

Crossrefs

Cf. A287385, A287386, A287388.

Programs

Mathematica

s = Nest[Flatten[# /. {0->{0, 1, 2}, 1->{2, 1, 0}, 2->{0, 2, 1}}] &, {0}, 9]; (*A287385*)
Flatten[Position[s, 0]]; (*A287386*)
Flatten[Position[s, 1]]; (*A287387*)
Flatten[Position[s, 2]]; (*A287388*)