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 A363862 #7 Jun 25 2023 05:58:59
%S A363862 1,2,7,49,831,39637,5593528,2363927011
%N A363862 Number of equivalence classes of unimodular n X n matrices with elements {0, 1}.
%C A363862 An integer matrix is unimodular if its determinant is -1 or +1. Two matrices are equivalent if one can be obtained from the other by permuting rows and columns.
%e A363862 For n=1, the only example is [1]. For n=2, representatives of the equivalence classes are [[1,0],[0,1]] and [[1,1],[0,1]].
%Y A363862 A306837 gives the total counts rather than equivalence classes.
%K A363862 nonn,hard,more
%O A363862 1,2
%A A363862 _Brendan McKay_, Jun 25 2023