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.

A258224 Row sums of A258223.

Original entry on oeis.org

1, 2, 13, 166, 3450, 105053, 4385297, 239389538, 16497800177, 1396841773631, 142194450687440, 17100401655609460, 2394468068218870494, 385647096554809325098, 70702689662684594772871, 14623755150209185924416598, 3385915623744083331349813602
Offset: 0

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Author

Alois P. Heinz, May 23 2015

Keywords

Crossrefs

Programs

  • Maple
    b:= proc(x, y, t, k) option remember; `if`(y>x or y<0, 0,
          `if`(x=0, 1, b(x-1, y-1, false, k)*`if`(t, (k*x+y)/y, 1)
                     + b(x-1, y+1, true, k)  ))
        end:
    A:= (n, k)-> b(2*n, 0, false, k):
    T:= proc(n,k) option remember;
           add(A(n, i)*(-1)^(k-i)*binomial(k, i), i=0..k)/k!
        end:
    a:= proc(n) option remember; add(T(n,k), k=0..n) end:
    seq(a(n), n=0..20);
  • Mathematica
    b[x_, y_, t_, k_] := b[x, y, t, k] = If[y > x || y < 0, 0,
         If[x == 0, 1, b[x - 1, y - 1, False, k]*If[t, (k*x + y)/y, 1]
                     + b[x - 1, y + 1, True, k]]];
    A[n_, k_] := b[2*n, 0, False, k];
    T[n_, k_] := Sum[A[n, i]*(-1)^(k - i)*Binomial[k, i], {i, 0, k}]/k!;
    a[n_] := Sum[T[n, k], {k, 0, n}];
    Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Apr 28 2022, after Alois P. Heinz *)

Formula

a(n) = Sum_{k=0..n} A258223(n,k).