A026498 a(n) = t(1+3n), where t = A001285 (Thue-Morse sequence).

2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 1, 2, 1, 1, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 1, 2, 1, 1, 1, 2, 2, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 1, 2, 1, 1, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2

Offset: 0

Author

Clark Kimberling

Keywords

• nonn

Links

• Michael De Vlieger, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A001285, A026492, A026513.

Programs

Mathematica

Array[1 + Mod[DigitCount[3 # + 1, 2, 1], 2] &, 105, 0] (* Michael De Vlieger, Oct 03 2019 *)

PARI

a(n)=1+hammingweight(3*n+1)%2 \\ Charles R Greathouse IV, May 09 2016

Extensions

Name and Pari adapted to match offset in A001285 by Sean A. Irvine, Oct 03 2019