OFFSET
0,2
COMMENTS
LINKS
Fung Lam, Table of n, a(n) for n = 0..1000
FORMULA
G.f.: c(x)/(1-4*x)^3, where c(x) is the g.f. for Catalan numbers.
Recurrence: (n+1)*a(n) = 128*(1-2*n)*a(n-4) + 32*(8*n-1)*a(n-3) - 24*(4*n+1)*a(n-2) + 2*(8*n+5)*a(n-1). - Fung Lam, Apr 13 2014
a(n) ~ 2^(2*n)*(n^2 - 8*n^(3/2)/(3*sqrt(Pi))). - Fung Lam, Apr 13 2014
Recurrence: n*(n+1)*a(n) = 2*n*(4*n+9)*a(n-1) - 8*(n+2)*(2*n+3)*a(n-2). - Vaclav Kotesovec, Apr 16 2014
MATHEMATICA
CoefficientList[Series[(1-Sqrt[1-4*x])/(2*x*(1-4*x)^3), {x, 0, 20}], x] (* Vaclav Kotesovec, Apr 16 2014 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
STATUS
approved