cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A135136 a(n) = floor(S2(n)/2) mod 2, where S2(n) is the binary weight of n.

Original entry on oeis.org

0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0
Offset: 0

Views

Author

Ctibor O. Zizka, Feb 13 2008

Keywords

Comments

A generalized Thue Morse sequence.
A class of generalized Thue-Morse sequences: Let F(t) be an integer function, m,k integers. Let Sk(n) be sum of digits of n; n in base-k. Then a(n)= F(Sk(n)) mod m is a generalized Thue-Morse sequence. Thue-Morse sequence has F(t)=t (identity function), S2(n), m=2,k=2. Interesting properties have sequences where F(Sk(n))=floor(Q*Sk(n)); Q is a positive rational number; a(n)=floor(Q*Sk(n)) mod m. Another interesting sequences are a(n)=(n*Sk(n)) mod m; a(n)=(n+Sk(n)) mod m.

References

  • J. P. Allouche and J. Shallit, Automatic Sequences: Theory, Applications, Generalizations, Cambridge University Press, 2003.

Crossrefs

Cf. A010060.

Programs

  • Mathematica
    Table[Mod[Floor[(Plus @@ IntegerDigits[n, 2])/2], 2], {n, 0, 90}] (* Stefan Steinerberger, Feb 14 2008 *)

Extensions

More terms from Stefan Steinerberger, Feb 14 2008