A079929 a(n)=(3*n+1)!/(n!*3^n).

1, 8, 280, 22400, 3203200, 717516800, 231757926400, 101973487616000, 58634755379200000, 42686101916057600000, 38374805622535782400000, 41751788517318931251200000, 54068566129928015970304000000

Offset

0,2

Links

Table of n, a(n) for n=0..12.

Formula

In Maple notation, hypergeometric generating function sum(a(n)*x^n/(n!)^2, n=0..infinity) = hypergeom([2/3, 4/3], [1], 9*x)

D-finite with recurrence a(n) -(3*n-1)*(3*n+1)*a(n-1)=0. - R. J. Mathar, Jul 27 2022

Maple

A079929 := proc(n)
    (3*n+1)!/(n!*3^n) ;
end proc:
seq(A079929(n), n=0..30) ; # R. J. Mathar, Jul 27 2022

Mathematica

Table[(3n+1)!/(n! 3^n), {n, 0, 30}] (* Harvey P. Dale, Jan 29 2021 *)

Crossrefs

Sequence in context: A281763 A280761 A247215 * A226415 A226346 A217488

Adjacent sequences: A079926 A079927 A079928 * A079930 A079931 A079932

Keyword

nonn

Author

Karol A. Penson, Jan 16 2003

Status

approved