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.

A135722 A000012 * A122890.

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 1, 1, 3, 5, 1, 1, 3, 15, 14, 1, 1, 3, 23, 84, 42, 1, 1, 3, 27, 244, 466, 132, 1, 1, 3, 28, 494, 2444, 2514, 429, 1, 1, 3, 28, 796, 8720, 22022, 13233, 1430, 1, 1, 3, 28, 1094, 24394, 128514, 181841, 68376, 4862
Offset: 0

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Author

Gary W. Adamson, Nov 25 2007

Keywords

Comments

Row sums = A003422: (1, 2, 4, 10, 34, 154, 874, ...).
Main diagonal = A000108, the Catalan numbers: (1, 1, 2, 5, 14, 42, 132, ...).

Examples

			First few rows of the triangle:
 1;
  1, 1;
  1, 1, 2;
  1, 1, 3,  5;
  1, 1, 3, 15,  14;
  1, 1, 3, 23,  84,   42;
  1, 1, 3, 27, 244,  466,  132;
  1, 1, 3, 28, 494, 2444, 2514, 429;
  ...
		

Crossrefs

Formula

A000012 * A122890 as infinite lower triangular matrices.