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 A332303 #4 Feb 09 2020 20:15:09
%S A332303 1,1,7,1849,65782211,633287284180541,2684646142383590108047885,
%T A332303 7376495464848567792567195041277565905,
%U A332303 18175605935440100610889032969797881598437325871194971,53139431374789917342401028242879020609739813068021830228099307511801461
%N A332303 a(n) = (n^2)! * [x^(n^2)] 1 / (1 - Sum_{k>=1} x^(n*k) / (n*k)!).
%t A332303 Table[(n^2)! SeriesCoefficient[1/(1 - Sum[x^(n k)/(n k)!, {k, 1, n}]), {x, 0, n^2}], {n, 0, 9}]
%Y A332303 Main diagonal of A260883.
%Y A332303 Cf. A000670, A326996.
%K A332303 nonn
%O A332303 0,3
%A A332303 _Ilya Gutkovskiy_, Feb 09 2020