A139379 A Jacobsthal Catalan convolution.

0, 1, 2, 6, 15, 41, 113, 327, 982, 3066, 9892, 32820, 111390, 385042, 1350722, 4795246, 17191535, 62139697, 226167557, 828085651, 3047683955, 11267975677, 41829610607, 155848125601, 582566960465, 2184167358991, 8211247681373

Offset

0,3

Comments

Second column of A139377. Row sums of A139377 give a(n+1).

Links

Table of n, a(n) for n=0..26.

Formula

G.f.: xc(x)/(1-x-2x^2), c(x) the g.f. of A000108; a(n)=sum{k=0..n, A000108(k)*A001045(n-k)};

D-finite with recurrence n*a(n) +(6-5*n)*a(n-1) +2*(n-3)*a(n-2) +4*(2*n-3)*a(n-3)=0. - R. J. Mathar, Oct 25 2012

Crossrefs

Sequence in context: A280788 A121328 A348012 * A236110 A362566 A280782

Adjacent sequences: A139376 A139377 A139378 * A139380 A139381 A139382

Keyword

easy,nonn

Author

Paul Barry, Apr 15 2008

Status

approved