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A101004 See formula line. 1
1, 13, 263, 7518, 280074, 12895572, 707902740, 45152821872, 3282497058384, 267944580145440, 24268165166553120, 2415271958048304000, 262018936450492859520, 30774091302535254992640, 3890462788950375951532800, 526745212429645673433446400, 76046696235437224473872640000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Vaclav Kotesovec, Table of n, a(n) for n = 1..328

David H. Bailey, Jonathan M. Borwein, David Broadhurst and M. L. Glasser, Elliptic integral evaluations of Bessel moments, arXiv:0801.0891

FORMULA

Let h_n = Sum_{ j=1..n } binomial(n,j)^2*binomial(2*j,j)*Sum_{ i=0..j-1 } 2/(n-i). Then a(n) = n!*h_n/4.

a(n) ~ n! * log(3) * 3^(2*n + 3/2) / (8*Pi*n). - Vaclav Kotesovec, Oct 06 2019

MAPLE

h := n-> add(binomial(n, j)^2*binomial(2*j, j)*add( 2/(n-i), i=0..j-1), j=1..n); [seq(n!*h(n)/4, n=1..30)];

MATHEMATICA

h[n_] := Sum[Binomial[n, j]^2*Binomial[2*j, j]*Sum[2/(n-i), {i, 0, j-1}], {j, 1, n}]; a[n_] := n!*h[n]/4; (* Jean-Fran├žois Alcover, May 31 2016 *)

CROSSREFS

Sequence in context: A034242 A142811 A034833 * A340936 A142931 A142262

Adjacent sequences:  A101001 A101002 A101003 * A101005 A101006 A101007

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Jan 20 2008, Jan 25 2008

STATUS

approved

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Last modified September 21 15:47 EDT 2021. Contains 347598 sequences. (Running on oeis4.)