A109268 Expansion of 1/((1-xc(x)-x^2c(x)^2)(1-x^2c(x))) with c(x) the g.f. of A000108.

1, 1, 4, 11, 36, 119, 407, 1418, 5018, 17971, 64989, 236915, 869518, 3209735, 11907644, 44368636, 165957615, 622880402, 2345005449, 8852862717, 33505203060, 127096279124, 483127286394, 1840030664115, 7020349647422

Offset

0,3

Comments

Diagonal sums of A109267.

Links

Table of n, a(n) for n=0..24.

Formula

G.f.: (2-x-x*sqrt(1-4x))(sqrt(1-4x)-x)/(2(1-4x-x^2)(1-x+x^3))

Crossrefs

Sequence in context: A054577 A206687 A106640 * A256960 A174993 A149238

Adjacent sequences: A109265 A109266 A109267 * A109269 A109270 A109271

Keyword

easy,nonn

Author

Paul Barry, Jun 24 2005

Status

approved