A013926 a(n) = (2*n)! * D_{2*n}, where D_{2*n} = (1/Pi) * Integral_{x=0..oo} [1 - x^(2*n) / Product_{j=1..n} (x^2+j^2)] dx.

1, 28, 1434, 118960, 14611150, 2494744728, 565526968692, 164368956804288, 59603021615454678, 26379919529434077640, 13996517446366589638636, 8769645281519454489332448, 6406629794568469259015608204

Offset

1,2

Links

Table of n, a(n) for n=1..13.

Formula

a(n) = n * Sum_{k=0..n-1} T(n, k) where T(n, 0) = n^(2*n) and for k > 0, T(n, k) = (-1) ^ k * (2 / k) * binomial(2*n-1, k-1) * (n-k)^(2*n+1). - Sean A. Irvine, Aug 30 2018

Crossrefs

Sequence in context: A118705 A249348 A366302 * A110696 A007222 A209265

Adjacent sequences: A013923 A013924 A013925 * A013927 A013928 A013929

Keyword

nonn

Author

Micha Hofri (hofri(AT)cs.rice.edu)

Status

approved