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

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

0,2

Comments

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

Links

Table of n, a(n) for n=0..44.

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

Example

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

Cf. A104455, A125906, A171568,

Sequence in context: A301624 A126791 A052179 * A126331 A013631 A331651

Adjacent sequences: A171586 A171587 A171588 * A171590 A171591 A171592

Keyword

nonn,tabl

Author

Philippe Deléham, Dec 12 2009

Status

approved