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.

A212808 Irregular triangle read by rows: row n gives number of cycles of length k in map on Catalan family of size n.

Original entry on oeis.org

1, 1, 1, 1, 2, 0, 1, 5, 0, 1, 1, 14, 0, 1, 0, 0, 0, 2, 42, 0, 2, 3, 0, 1, 4, 132, 0, 2, 0, 0, 0, 14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 429, 0, 2, 7, 0, 0, 28, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 2, 0, 0, 0, 1
Offset: 0

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Author

N. J. A. Sloane, May 29 2012

Keywords

Comments

Length of n-th row: A057545(n)+1.

Examples

			Triangle begins
  1 1
  1 1
  2 0 1
  5 0 1 1
  14 0 1 0 0 0 2
  42 0 2 3 0 1 4
  132 0 2 0 0 0 14 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1
  429 0 2 7 0 0 28 0 0 1 1 0 0 0 0 1 0 0 0 0 2 0 0 0 1 ...
  ...
		

Crossrefs

Formula

T(n,0) = A000108(n).
T(n,0) = sum_{k>0} k*T(n,k) (see Donaghey, paragraph before (13)).