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 A052271 #22 May 02 2022 10:31:48 %S A052271 1,4,76,8240,7880456,79846389608,9178323524804624, %T A052271 12508419942924578958856,209493560585995285291677153144, %U A052271 44407122853769773657258254744483639216,122042291850117110186411151373496788803833567344,4435666701292795500500326090033525002278314431436080593856 %N A052271 Number of n X n matrices over GF(4) under row and column permutations. %H A052271 Alois P. Heinz, <a href="/A052271/b052271.txt">Table of n, a(n) for n = 0..26</a> %H A052271 <a href="/index/Mat#inequiv">Index to number of inequivalent matrices modulo permutation of rows and columns</a> %F A052271 a(n) = sum_{1*s_1+2*s_2+...=n, 1*t_1+2*t_2+...=n} (fixA[s_1, s_2, ...;t_1, t_2,...]/(1^s_1*s_1!*2^s_2*s_2!*...*1^t_1*t_1!*2^t_2*t_2!*...)) where fixA[...] = 4^sum_{i, j>=1} (gcd(i,j)*s_i*t_j). - _Christian G. Bower_, Dec 18 2003 %Y A052271 Cf. A002724, A052269, A052272, A091061. %Y A052271 Column k=4 of A246106. %K A052271 nonn %O A052271 0,2 %A A052271 _Vladeta Jovovic_, Feb 05 2000 %E A052271 More terms from _Alois P. Heinz_, Jul 31 2014