A027259 a(n) = Sum_{k=0..2n-2} T(n,k) * T(n,k+2), with T given by A025177.

5, 40, 342, 2941, 25333, 218659, 1891683, 16403283, 142548639, 1241293314, 10829045472, 94632148659, 828235716571, 7258991679448, 63701900660206, 559673483274827, 4922447330226279, 43336501329817600, 381873520840930490, 3367815295820010367, 29724409053210972087

Offset

2,1

Links

Table of n, a(n) for n=2..22.

Crossrefs

Sequence in context: A067412 A355355 A078846 * A007036 A264227 A052798

Adjacent sequences: A027256 A027257 A027258 * A027260 A027261 A027262

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms from Sean A. Irvine, Oct 26 2019

Status

approved