A132866 Expansion of 1/(1-6x*c(7x)), where c(x) is the g.f. of A000108.

1, 6, 78, 1308, 24942, 513876, 11148012, 250917624, 5805563310, 137233668900, 3299955883428, 80468668049160, 1985171406618156, 49458290358431688, 1242613072013591832, 31448339835422435568

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Formula

G.f.: 7/(4 + 3*sqrt(1-28*x)).

a(n) = 7^n*Sum_{j=0..n} (6/7)^j*j*binomial(2n-j,n)/(2n-j) for n >= 1. - Emeric Deutsch, Nov 19 2007

a(n) = Sum_{k=0..n} A039599(n,k)*(-1)^k*7^(n-k). - Philippe Deléham, Dec 11 2007

Maple

g:=7/(4+3*sqrt(1-28*x)): gser:=series(g, x=0, 18): seq(coeff(gser, x, n), n=0..15); # Emeric Deutsch, Nov 19 2007

Crossrefs

Sequence in context: A358956 A268555 A131926 * A279444 A094419 A229044

Adjacent sequences: A132863 A132864 A132865 * A132867 A132868 A132869

Keyword

nonn

Author

Philippe Deléham, Nov 18 2007

Extensions

More terms from Emeric Deutsch, Nov 19 2007

Status

approved