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

Author

Paul Barry, Apr 15 2008

Keywords

• easy
• nonn

Comments

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

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