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.

A151930 First differences of A001316.

Original entry on oeis.org

1, 0, 2, -2, 2, 0, 4, -6, 2, 0, 4, -4, 4, 0, 8, -14, 2, 0, 4, -4, 4, 0, 8, -12, 4, 0, 8, -8, 8, 0, 16, -30, 2, 0, 4, -4, 4, 0, 8, -12, 4, 0, 8, -8, 8, 0, 16, -28, 4, 0, 8, -8, 8, 0, 16, -24, 8, 0, 16, -16, 16, 0, 32, -62, 2, 0, 4, -4, 4, 0, 8, -12, 4, 0, 8, -8, 8, 0, 16, -28, 4, 0, 8, -8, 8, 0, 16, -24, 8, 0, 16, -16, 16, 0, 32
Offset: 0

Views

Author

N. J. A. Sloane, Aug 10 2009

Keywords

Comments

Net increase in number of ON cells at generation n of 1-D CA using Rule 90.

Crossrefs

Programs

  • Maple
    nmax := 94: A001316 := n -> if n<=-1 then 0 else 2^add(i, i=convert(n, base, 2)) fi: for p from 0 to ceil(log[2](nmax))+1 do for n from 0 to nmax/(p+2)+1 do a((2*n+1)*2^p-1) := (2-2^p) * A001316(n) od: od: seq(a(n), n=0..nmax); # Johannes W. Meijer, Jan 25 2013

Formula

a((2*n+1)*2^p-1) = (2-2^p) * A001316(n), p >= 0 and n >=0. - Johannes W. Meijer, Jan 25 2013
G.f.: -1/x + ((1 - x)/x)*Product_{k>=0} (1 + 2*x^(2^k)). - Ilya Gutkovskiy, Feb 28 2017