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.

A229054 Autosequence preceding -A226158(n).

Original entry on oeis.org

0, 0, 0, 1, 2, 2, 1, 1, 4, 4, -13, -13, 142, 142, -1931, -1931, 36296, 36296, -893273, -893273, 27927346, 27927346, -1081725559, -1081725559, 50861556172, 50861556172, -2854289486309, -2854289486309
Offset: 0

Views

Author

Paul Curtz, Sep 12 2013

Keywords

Comments

Extension of the difference table of Genocchi numbers A226158(n). The signs are changed.
Consider the difference table of -A226158:
0, 1, 1, 0 -1, 0,
1, 0, -1, -1, 1, 3,
-1, -1, 0, 2, 2, -6,
0, 1, 2, 0, -8, -8,
1, 1, -2, -8, 0, 56,
0, -3, -6, 8, 56, 0, etc.
Upon the table, we prolonged the main diagonal by 0 followed by 0 on the same row. Hence
0, 0, 0, 1, 2, 2, 1, 1,
0, 0, 1, 1, 0, -1, 0, 3, = 0 followed by -A226158.
0, 1, 0, -1, -1, 1, 3, -3,
1, -1, -1, 0, 2, 2, -6, -14,
-2, 0, 1, 2, 0, -8, -8, 48,
2, 1, 1, -2, -8, 0, 56, 56,
-1, 0, -3, -6, 8, 56, 0, -608,
1, -3, -3, 14, 48, -56, -608, 0, etc.
The first row, a(n), is equal to its inverse binomial transform signed, the main diagonal of the difference table is composed of 0's, so it is an autosequence of the first kind.

Programs

  • Mathematica
    max = 24; p[0, ] = 1; p[n, x_] := (1+x)*((1+x)^(n-1) + x^(n-1))/2; t = Table[Coefficient[p[n, x], x, k], {n, 0, max+2}, {k, 0, max+2}]; a[n_] := Inverse[t][[All, 3]][[n+3]]; A133135 = Table[a[n], {n, 0, max}]; Join[{0, 0, 0}, Table[(-1)^n*A133135[[n+1]], {n, 0, max}]]
    (* or *)
    g[n_ /; n < 3] = 0; g[3] = -1; g[n_] := (n-2)*EulerE[n-3, 0]; Table[-g[n], {n, 0, 27}] // Accumulate (* Jean-François Alcover, Sep 12 2013 *)

Formula

a(n) = 0, 0, 0 followed by (-1)^n * A133135(n).