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.

A088172 First differences of A019300.

Original entry on oeis.org

1, 2, 3, 7, 13, 26, 53, 106, 211, 422, 845, 1689, 3379, 6758, 13515, 27031, 54061, 108122, 216245, 432489, 864979, 1729958, 3459915, 6919830, 13839661, 27679322, 55358643, 110717287, 221434573, 442869146, 885738293, 1771476586, 3542953171
Offset: 1

Views

Author

Gary W. Adamson, Sep 21 2003

Keywords

Comments

Partial sums give A019300, while partial sums mod 2 = the Thue-Morse sequence, A010060. a(n) mod 2 = A035263: 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, ...

Crossrefs

Programs

  • Mathematica
    tm = Table[ If[ OddQ[ Count[ IntegerDigits[n, 2], 1]], 1, 0], {n, 0, 35}]; Table[ FromDigits[ Take[ tm, n + 1], 2] - FromDigits[ Take[ tm, n], 2], {n, 1, 33}] (* Robert G. Wilson v *)

Formula

a(n+1) = 2*a(n) + 0 or +-1. - Robert G. Wilson v, Sep 27 2003
a(n+1) = 2*a(n) + A029883(n). - Philippe Deléham, Mar 21 2004

Extensions

More terms from Robert G. Wilson v, Sep 27 2003