This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A100734 #15 Sep 08 2022 08:45:15
%S A100734 1,120,3628800,1307674368000,2432902008176640000,
%T A100734 15511210043330985984000000,265252859812191058636308480000000,
%U A100734 10333147966386144929666651337523200000000
%N A100734 a(n) = (5*n)!.
%H A100734 Vincenzo Librandi, <a href="/A100734/b100734.txt">Table of n, a(n) for n = 0..90</a>
%F A100734 E.g.f.: 1/(1-x^5).
%F A100734 From _Ilya Gutkovskiy_, Jan 20 2017: (Start)
%F A100734 a(n) ~ sqrt(2*Pi)*5^(5*n + 1/2)*n^(5*n + 1/2)/exp(5*n).
%F A100734 Sum_{n>=0} 1/a(n) = A269296. (End)
%t A100734 (5*Range[0,10])! (* _Harvey P. Dale_, May 06 2015 *)
%o A100734 (Magma) [Factorial(5*n): n in [0..10]]; // _Vincenzo Librandi_, Sep 24 2011
%Y A100734 Cf. A000142, A010050, A100732, A100733, A268506, A269296.
%K A100734 nonn,easy
%O A100734 0,2
%A A100734 _Ralf Stephan_, Dec 08 2004