A216195 Abelian complexity function of the period-doubling sequence (A096268).

2, 2, 3, 2, 3, 3, 3, 2, 3, 3, 4, 3, 4, 3, 3, 2, 3, 3, 4, 3, 4, 4, 4, 3, 4, 4, 4, 3, 4, 3, 3, 2, 3, 3, 4, 3, 4, 4, 4, 3, 4, 4, 5, 4, 5, 4, 4, 3, 4, 4, 5, 4, 5, 4, 4, 3, 4, 4, 4, 3, 4, 3, 3, 2, 3, 3, 4, 3, 4, 4, 4, 3, 4, 4, 5, 4, 5, 4, 4, 3, 4, 4, 5, 4, 5, 5, 5, 4, 5, 5, 5, 4, 5, 4, 4, 3, 4, 4, 5

Offset: 1

Author

Nathan Fox, Mar 12 2013

Keywords

• nonn
• easy

References

• Michel Rigo, Formal Languages, Automata and Numeration Systems, 2 vols., Wiley, 2014. Mentions this sequence - see "List of Sequences" in Vol. 2.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..10000
• Nathan Fox, Python code to generate sequence

Crossrefs

Cf. A007302, A096268.

Programs

Mathematica

a[n_]:=Count[BitXor[b1=IntegerDigits[n, 2]; b3=IntegerDigits[3*n, 2]; PadLeft[b1, Length[b3]], b3], 1]; Table[a[n] + 1, {n, 1, 100}] (* Vincenzo Librandi, Jan 13 2017 *)

Formula

a(1) = 2; a(2n) = a(n); a(4n-1) = a(n) + 1; a(4n+1) = a(n) + 1.

a(n) = A007302(n) + 1.