A287437 Positions of 2 in A053838.

3, 5, 7, 11, 13, 18, 19, 24, 26, 29, 31, 36, 37, 42, 44, 48, 50, 52, 55, 60, 62, 66, 68, 70, 74, 76, 81, 83, 85, 90, 91, 96, 98, 102, 104, 106, 109, 114, 116, 120, 122, 124, 128, 130, 135, 138, 140, 142, 146, 148, 153, 154, 159, 161, 163, 168, 170, 174, 176

Offset: 1

Author

Clark Kimberling, May 26 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.

Does this differ from A026603? - R. J. Mathar, Jun 14 2017

Links

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

Crossrefs

Cf. A053838, A287435, A287436.

Programs

Mathematica

s = Nest[Flatten[# /. {0->{0, 1, 2}, 1->{1, 2, 0}, 2->{2, 0, 1}}] &, {0}, 9]; (*A053838*)
Flatten[Position[s, 0]]; (*A287435*)
Flatten[Position[s, 1]]; (*A287436*)
Flatten[Position[s, 2]]; (*A287437*)

Formula

a(n) + A053838(n-1) = 3n.

Extensions

The definition refers to a different offset in A053838. - R. J. Mathar, May 30 2017