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 A286393 #29 Apr 15 2021 15:18:53 %S A286393 1,7,406,5105212,4154189102413,167633579843887699759, %T A286393 331466355732596931093508048522, %U A286393 32115447190132359991237336502881651018804,152470060954479462517322396167243320349298407119379801 %N A286393 Number of inequivalent n X n matrices over GF(7) under action of dihedral group of the square D_4. %C A286393 Burnside's orbit-counting lemma %H A286393 María Merino, <a href="/A286393/b286393.txt">Table of n, a(n) for n = 0..34</a> %H A286393 M. Merino and I. Unanue, <a href="https://doi.org/10.1387/ekaia.17851">Counting squared grid patterns with Pólya Theory</a>, EKAIA, 34 (2018), 289-316 (in Basque). %F A286393 a(n) = (1/8)*(7^(n^2) + 2*7^(n^2/4) + 3*7^(n^2/2) + 2*7^((n^2 + n)/2)) if n is even; %F A286393 a(n) = (1/8)*(7^(n^2) + 2*7^((n^2 + 3)/4) + 7^((n^2 + 1)/2) + 4*7^((n^2 + n)/2)) if n is odd. %Y A286393 Column k=7 of A343097. %Y A286393 Cf. A054247, A054739, A054751, A054752, A286392. %K A286393 nonn %O A286393 0,2 %A A286393 _María Merino_, Imanol Unanue, _Yosu Yurramendi_, May 08 2017