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 A338437 #5 Oct 28 2020 09:29:13
%S A338437 1,1,2,9,32,300,864,17612,74752,1152792,6470400,220057992,719622144,
%T A338437 40754156352,192835098624,4787867880000,55181218873344,
%U A338437 3071730630989952,11004144881762304,1179255538492239744,5720352215040000000,253837962769406045184,3262870639485701849088
%N A338437 a(n) = n! * [x^n] Product_{k=1..n, gcd(n,k) = 1} 1 / (1 - x^k/k).
%t A338437 Table[n! SeriesCoefficient[Product[1/(1 - Boole[GCD[n, k] == 1] x^k/k), {k, 1, n}], {x, 0, n}], {n, 0, 22}]
%Y A338437 Cf. A007841, A057562, A338439.
%K A338437 nonn
%O A338437 0,3
%A A338437 _Ilya Gutkovskiy_, Oct 27 2020