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 A091059 #17 May 02 2022 09:45:44
%S A091059 1,1,5,18,173,2812,126446,16821330,7343033248,10733521835504,
%T A091059 52867612881649880,882178115128903807148,50227997322259477864188380,
%U A091059 9837048598740464300126599181536,6681839615514161335727724211992609234,15867777966020615016155969700335142344866474
%N A091059 Number of n X n matrices over symbol set {1,2} equivalent under any permutation of row, columns or the symbol set.
%H A091059 Alois P. Heinz, <a href="/A091059/b091059.txt">Table of n, a(n) for n = 0..20</a>
%H A091059 C. G. Bower, <a href="/A091057/a091057.html">Explanation of A091057-A091062</a>
%H A091059 <a href="/index/Mat#inequiv">Index to number of inequivalent matrices modulo permutation of rows and columns</a>
%F A091059 a(n) = sum {1*s_1+2*s_2+...=n, 1*t_1+2*t_2+...=n, 1*u_1+2*u_2=2} (fixA[s_1, s_2, ...;t_1, t_2, ...;u_1, u_2] /(1^s_1*s_1!*2^s_2*s_2!*... *1^t_1*t_1!*2^t_2*t_2!*... *1^u_1*u_1!*2^u_2*u_2!)) where fixA[...] = prod {i, j>=1} ( (sum {d|lcm(i, j)} (d*u_d))^(gcd(i, j)*s_i*t_j)).
%Y A091059 Cf. A091057-A091062.
%Y A091059 Main diagonal of A242093.
%Y A091059 Column k=2 of A242095.
%K A091059 nonn
%O A091059 0,3
%A A091059 _Christian G. Bower_, Dec 17 2003
%E A091059 a(15) from _Alois P. Heinz_, Aug 14 2014