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.

A171589 Riordan array (f(x), x*f(x)) where f(x) is the g.f. of A104455.

Original entry on oeis.org

1, 4, 1, 17, 8, 1, 77, 50, 12, 1, 371, 290, 99, 16, 1, 1890, 1647, 703, 164, 20, 1, 10095, 9366, 4644, 1380, 245, 24, 1, 56040, 53853, 29592, 10434, 2385, 342, 28, 1, 320795, 314234, 185411, 74084, 20345, 3782, 455, 32, 1
Offset: 0

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Author

Philippe Deléham, Dec 12 2009

Keywords

Comments

Equal to B*A171568 = A125906*B^(-1), B = A007318.

Examples

			Triangle begins :
1
4, 1
17, 8, 1
77, 50, 12, 1
371, 290, 99, 16, 1
1890, 1647, 703, 164, 20, 1
10095, 9366, 4644, 1380, 245, 24, 1
Production matrix begins
4, 1
1, 4, 1
1, 1, 4, 1
1, 1, 1, 4, 1
1, 1, 1, 1, 4, 1
1, 1, 1, 1, 1, 4, 1
1, 1, 1, 1, 1, 1, 4, 1
1, 1, 1, 1, 1, 1, 1, 4, 1
... - _Philippe Deléham_, Mar 05 2013
		

Crossrefs

Formula

T(n,0)-T(n,1)=3^n.
T(n,k) = T(n-1,k-1) + 4*T(n-1,k) + sum_{i, i>=0} T(n-1,k+1+i). - Philippe Deléham, Feb 23 2012