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 A189102 #9 Sep 12 2021 14:27:51 %S A189102 1,1,1,4,4,48,48,192,1728,34560,34560,414720,414720,2903040,130636800, %T A189102 2090188800,2090188800,25082265600,25082265600,501645312000, %U A189102 31603654656000,347640201216000,347640201216000,5562243219456000,139056080486400000 %N A189102 Greatest common divisor of n! and its arithmetic derivative. %H A189102 Nathaniel Johnston, <a href="/A189102/b189102.txt">Table of n, a(n) for n = 1..200</a> %F A189102 a(n) = gcd(n!,n!') = gcd(A000142(n),A068311(n)). %e A189102 n = 5: 5! = 120, 120' = 244, gcd(120,244) = 4 -> a(5) = 4 %Y A189102 A068311, A083346, A083346, A085731, A086130, A189100 %K A189102 nonn %O A189102 1,4 %A A189102 _Giorgio Balzarotti_, Apr 16 2011