A126157 Main diagonal and central terms of symmetric triangle A126155.

1, 5, 55, 1415, 69025, 5403005, 616437655, 96365988815, 19756766836225, 5140259013390005, 1654190282113104055, 645005323804145184215, 299613583126435893179425, 163464903833408195554809005

Offset

0,2

Links

Table of n, a(n) for n=0..13.

Formula

a(n)=Sum_{k, 0<=k<=n}A130847(n,k)*4^k. - Philippe Deléham, Jul 22 2007

Crossrefs

Cf. A126155; A126156 (column 0), A126158 (diagonal).

Sequence in context: A056600 A177819 A126456 * A176267 A105715 A111821

Adjacent sequences: A126154 A126155 A126156 * A126158 A126159 A126160

Keyword

nonn

Author

Paul D. Hanna, Dec 20 2006

Status

approved