OFFSET
0,3
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
FORMULA
Appears to be a(n) = 4^(n+1)*Pi^(-1/2)*Gamma(n+3/2)/Gamma(n+5)*(n+1)*n*(n^2+3*n+1). - Mark van Hoeij, Oct 30 2011
a(n) ~ 2^(2*n+2) * sqrt(n/Pi). - Amiram Eldar, Sep 04 2025
MATHEMATICA
Table[n*(n^2+3*n+1)*Binomial[2*n+2, n]/((n+3)*(n+4)), {n, 0, 20}] (* Vaclav Kotesovec, Oct 27 2012 *)
PROG
(PARI) a(n)=n*(n^2+3*n+1)*binomial(2*n+2, n)/((n+3)*(n+4)); \\ Joerg Arndt, May 04 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Corrected and extended by N. J. A. Sloane, Apr 21 2000
STATUS
approved