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 A091060 #14 Dec 19 2021 13:57:00
%S A091060 1,1,8,139,15412,10805764,50459685390,1601741458883376,
%T A091060 355089431048672347272,563306081052639719480623715,
%U A091060 6532991278768207315727662508956920,564259839851988012635404101255119945332425,368759675849515285894392091271956490586673272192738
%N A091060 Number of n X n matrices over symbol set {1,2,3} equivalent under any permutation of row, columns or the symbol set.
%H A091060 C. G. Bower, <a href="/A091057/a091057.html">Explanation of A091057-A091062</a>
%F A091060 a(n) = sum {1*s_1+2*s_2+...=n, 1*t_1+2*t_2+...=n, 1*u_1+2*u_2+...=3} (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 A091060 Cf. A091057-A091062.
%Y A091060 Column k=3 of A242095.
%K A091060 nonn
%O A091060 0,3
%A A091060 _Christian G. Bower_, Dec 17 2003
%E A091060 a(11)-a(12) from _Alois P. Heinz_, Aug 14 2014