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 A338436 #5 Oct 28 2020 09:29:06
%S A338436 1,1,2,9,28,245,726,11480,48560,735705,4352050,98329550,483122388,
%T A338436 15543026746,105478954140,2717386363515,25322712724800,
%U A338436 896697825211141,6457456535543802,307183340680888754,2920059397230745400,107461248960479482740,1360407935621917573380
%N A338436 a(n) = n! * [x^n] Product_{k=1..n, gcd(n,k) = 1} 1 / (1 - x^k/k!).
%t A338436 Table[n! SeriesCoefficient[Product[1/(1 - Boole[GCD[n, k] == 1] x^k/k!), {k, 1, n}], {x, 0, n}], {n, 0, 22}]
%Y A338436 Cf. A005651, A057562, A338438.
%K A338436 nonn
%O A338436 0,3
%A A338436 _Ilya Gutkovskiy_, Oct 27 2020