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.

A064338 Row sums of signed triangle A064334.

Original entry on oeis.org

1, 2, 3, 3, 3, 4, -6, 49, -178, 76, 8633, -124131, 1202662, -8252662, 16009623, 730544913, -17236420029, 256679586178, -2787185606474, 15947981601793, 215110909342463, -9723413157539188, 216257810122284716, -3515999949642686709
Offset: 0

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Author

Wolfdieter Lang, Sep 21 2001

Keywords

Crossrefs

Cf. A064339 (row sums of unsigned triangle A064334).

Programs

  • Maple
    f:= proc(n) local k; 1 + add(simplify(hypergeom([1-n+k,n-k],[-n+k],-k)),k=0..n-1) end proc:
    map(f, [$0..50]); # Robert Israel, Jan 03 2019
  • Mathematica
    a[n_] := If[n == 0, 1, Sum[(n-k-j)*Binomial[n-k-1+j, j]* (-k)^j/(n-k), {k, 1, n-1}, {j, 0, n-k-1}] + 2];
    Table[a[n], {n, 0, 50}] (* Jean-François Alcover, Feb 06 2023 *)

Formula

a(n) = 1 + Sum_{0<=k<=n-1} hypergeom([1-n+k,n-k],[-n+k],-k). - Robert Israel, Jan 03 2019