OFFSET
0,2
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
KEYWORD
nonn
AUTHOR
Philippe Deléham, Nov 18 2007
EXTENSIONS
More terms from Emeric Deutsch, Nov 19 2007
STATUS
approved