OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..63
FORMULA
a(n) = A134772(2*n+1). - G. C. Greubel, Oct 13 2023
a(n) ~ sqrt(Pi) * 2^(18*n + 11) * n^(8*n + 9/2) / (3^(2*n+1) * exp(8*n + 3/4)). - Vaclav Kotesovec, Oct 21 2023
MATHEMATICA
A134772[n_]:= ((4*n)!/(24)^n)*Hypergeometric1F1[-n, 1/2-2*n, -3/2];
Table[A144549[n], {n, 0, 20}] (* G. C. Greubel, Oct 13 2023 *)
PROG
(Magma)
B:=Binomial; F:=Factorial;
A134772:= func< n | F(4*n)/(24)^n *(&+[B(n, j)*B(2*n, j)*(-6)^j/(F(j)*B(2*j, j)*B(4*n, 2*j)) : j in [0..n]]) >;
[A144649(n): n in [0..20]]; // G. C. Greubel, Oct 13 2023
(SageMath)
def A134772(n): return (factorial(4*n)/(24)^n)* simplify(hypergeometric([-n], [1/2-2*n], -3/2))
[A144649(n) for n in range(21)] # G. C. Greubel, Oct 13 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 18 2009
STATUS
approved