A010794 a(n) = n!*(n+5)!/5!.

1, 6, 84, 2016, 72576, 3628800, 239500800, 20118067200, 2092278988800, 263627152588800, 39544072888320000, 6959756828344320000, 1419790392982241280000, 332230951957844459520000, 88373433220786626232320000, 26512029966235987869696000000

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for sequences related to factorial numbers.

Formula

From Amiram Eldar, Sep 27 2022: (Start)

Sum_{n>=0} 1/a(n) = 120*BesselI(5,2).

Sum_{n>=0} (-1)^n/a(n) = 120*BesselJ(5,2). (End)

Maple

f := n->n!*(n+5)!/5!;

Mathematica

With[{c=5!}, Table[(n!(n+5)!)/c, {n, 0, 20}]] (* Harvey P. Dale, Oct 03 2011 *)

Prog

(Magma) [Factorial(n)*Factorial(n+5) / Factorial(5): n in [0..20]]; // Vincenzo Librandi, Oct 04 2011
(PARI) a(n)=n!^2*binomial(n+5, 5) \\ Charles R Greathouse IV, Oct 23 2023

Crossrefs

Cf. A010791, A010792, A010793, A010795.

Sequence in context: A014062 A147626 A123312 * A177560 A177562 A273935

Adjacent sequences: A010791 A010792 A010793 * A010795 A010796 A010797

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Harvey P. Dale, Oct 03 2011

Status

approved