A100734 a(n) = (5*n)!.
1, 120, 3628800, 1307674368000, 2432902008176640000, 15511210043330985984000000, 265252859812191058636308480000000, 10333147966386144929666651337523200000000
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..90
Programs
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Magma
[Factorial(5*n): n in [0..10]]; // Vincenzo Librandi, Sep 24 2011
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Mathematica
(5*Range[0,10])! (* Harvey P. Dale, May 06 2015 *)
Formula
E.g.f.: 1/(1-x^5).
From Ilya Gutkovskiy, Jan 20 2017: (Start)
a(n) ~ sqrt(2*Pi)*5^(5*n + 1/2)*n^(5*n + 1/2)/exp(5*n).
Sum_{n>=0} 1/a(n) = A269296. (End)