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.

A075780 Triangle T(n,k) = f(n,k,n-2), n >= 2, 1 <= k <= n-1, where f is given below.

Original entry on oeis.org

0, 3, 3, 12, 14, 12, 30, 45, 45, 30, 60, 114, 138, 114, 60, 105, 245, 357, 357, 245, 105, 168, 468, 808, 960, 808, 468, 168, 252, 819, 1647, 2286, 2286, 1647, 819, 252, 360, 1340, 3090, 4935, 5740, 4935, 3090, 1340, 360, 495, 2079, 5423, 9834, 13090, 13090, 9834, 5423
Offset: 2

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Author

N. J. A. Sloane, Oct 17 2002

Keywords

Crossrefs

Cf. A014410 and A007318 for f(n, k, n), A075779 and A075798 for f(n, k, n-1) and A075780 and A075837 for f(n, k, n-2).

Programs

  • Maple
    f := proc(n,p,k) convert( binomial(n,k)*hypergeom([1-k,-p,p-n],[1-n,1],1), `StandardFunctions`); end;
  • Mathematica
    t[n_, k_] := n*(n-1)/2*HypergeometricPFQ[{-k, 3-n, k-n}, {1, 1-n}, 1]; Table[t[n, k], {n, 2, 12}, {k, 1, n-1}] // Flatten (* Jean-François Alcover, Jan 14 2014 *)

Formula

f(n, p, k) = binomial(n, k)*hypergeom([1-k, -p, p-n], [1-n, 1], 1).