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

Author

Philippe Deléham, Nov 18 2007

Keywords

• nonn

Programs

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

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

Extensions

More terms from Emeric Deutsch, Nov 19 2007