A248709 a(n) = f(5*n)/(f(n-2)*f(n-1)*f(n)*f(n+1)*f(n+2)), where f(k) = k!.

12600, 37837800, 97772875200, 247365374256000, 629483036137956000, 1621828071329658192000, 4234824783966213204768000, 11198994141198650820008976000, 29959571750765218953790679280000, 80980722442318386832096206093840000, 220917676017677910841226480887103040000

Offset

2,1

Comments

These are multinomial coefficients.

Links

Clark Kimberling, Table of n, a(n) for n = 2..200

Formula

a(n) ~ 5^(5*n+1/2) / (4*Pi^2*n^2). - Vaclav Kotesovec, Oct 19 2014

Example

a(3) = 15!/(1!*2!*3!*4!*5!) = 37837800.

Mathematica

Table[(5 n)!/((n - 2)! (n - 1)! n! (n + 1)! (n + 2)!), {n, 2, 20}]

Prog

(Sage) [factorial(5*n)/(factorial(n - 2)*factorial(n - 1)*factorial(n)*factorial(n + 1)*factorial(n + 2)) for n in range(2, 14)] # Stefano Spezia, Aug 16 2024

Crossrefs

Cf. A000142, A001700, A248707, A248708, A248710.

Sequence in context: A190109 A272516 A246231 * A352586 A261860 A187136

Adjacent sequences: A248706 A248707 A248708 * A248710 A248711 A248712

Keyword

nonn,easy

Author

Clark Kimberling, Oct 12 2014

Status

approved