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.

A134399 Matrix product of Binomial triangle A007318 and triangle with (1, 1, 2, 3, 4, 5, ...) in the main diagonal and the rest zeros.

Original entry on oeis.org

1, 1, 1, 1, 2, 2, 1, 3, 6, 3, 1, 4, 12, 12, 4, 1, 5, 20, 30, 20, 5, 1, 6, 30, 60, 60, 30, 6, 1, 7, 42, 105, 140, 105, 42, 7, 1, 8, 56, 168, 280, 280, 168, 56, 8, 1, 9, 72, 252, 504, 630, 504, 252, 72, 9
Offset: 0

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Author

Gary W. Adamson, Oct 23 2007

Keywords

Comments

Row sums = A005183: (1, 2, 5, 13, 33, 81, 193, ...).

Examples

			First few rows of the triangle:
  1;
  1, 1;
  1, 2,  2;
  1, 3,  6,   3;
  1, 4, 12,  12,   4;
  1, 5, 20,  30,  20,   5;
  1, 6, 30,  60,  60,  30,  6;
  1, 7, 42, 105, 140, 105, 42, 7;
  ...
		

Crossrefs

Programs

  • Mathematica
    Table[Max[k, 1]*Binomial[n, k], {n, 0, 10}, {k, 0, n}] (* Paolo Xausa, May 03 2024 *)

Formula

T(n,0) = 1; T(n,k) = k*binomial(n,k) for 1 <= k <= n. [corrected by Paolo Xausa, May 03 2024]

Extensions

Corrected and edited by Olivier Gérard, Aug 01 2013