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.

A229659 9-section a(9n+k) gives k-th differences of a for k=0..8 with a(n)=0 for n<8 and a(8)=1.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, -8, 0, 0, 0, 0, 0, 0, 1, -7, 28, 0, 0, 0, 0, 0, 1, -6, 21, -56, 0, 0, 0, 0, 1, -5, 15, -35, 70, 0, 0, 0, 1, -4, 10, -20, 35, -56, 0, 0, 1, -3, 6, -10, 15, -21, 28, 0, 1, -2, 3, -4, 5, -6, 7, -8, 1, -1, 1, -1
Offset: 0

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Author

Alois P. Heinz, Sep 27 2013

Keywords

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember; local m, q;
          m:= irem(n, 9, 'q'); `if`(n<9, `if`(n=8, 1, 0),
          add(a(q+m-j)*(-1)^j*binomial(m, j), j=0..m))
        end:
    seq(a(n), n=0..100);

Formula

a(9*n+k) = Sum_{j=0..k} (-1)^j * C(k,j) * a(n+k-j) for k=0..8.