A034269 a(n) = f(n,n+2) where f is given in A034261.

0, 1, 11, 76, 435, 2255, 11011, 51688, 236028, 1056210, 4654430, 20266312, 87402185, 374008635, 1590144675, 6724160400, 28303504680, 118665923310, 495820606410, 2065492595400, 8581809094950, 35572994871414, 147149351758926, 607555878211376

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.

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

Sequence in context: A036427 A122589 A302382 * A256597 A245561 A056914

Adjacent sequences: A034266 A034267 A034268 * A034270 A034271 A034272

Keyword

nonn,easy

Author

Clark Kimberling

Extensions

Corrected and extended by N. J. A. Sloane, Apr 21 2000

Status

approved