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A248708
a(n) = f(4*n+2)/(f(n-1)*f(n)*f(n+1)*f(n+2)), where f(k) = k!.
4
60, 12600, 2522520, 514594080, 107550162720, 22969641895200, 4995897112206000, 1103284402265073600, 246784661070292144800, 55803246694136969227200, 12736017918577260592084800, 2930174751896446667689440000, 678879630375093886522676256000, 158257286142440155623613107216000
OFFSET
1,1
COMMENTS
These are multinomial coefficients.
LINKS
FORMULA
a(n) ~ 2^(8*n+7/2) / (Pi^(3/2) * n^(3/2)). - Vaclav Kotesovec, Oct 19 2014
EXAMPLE
a(2) = 10!/(1!*2!*3!*4!) = 12600.
MATHEMATICA
Table[(4 n + 2)!/((n - 1)! n! (n + 1)! (n + 2)!), {n, 1, 20}]
PROG
(Sage) [factorial(4*n + 2)/(factorial(n - 1)* factorial(n)*factorial(n + 1)*factorial(n + 2)) for n in range(1, 14)] # Stefano Spezia, Aug 16 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Oct 12 2014
STATUS
approved