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 A306837 #12 Jun 25 2023 09:54:09
%S A306837 1,6,168,20040,9702720,18480102480,135491563468800,3766962568171582080
%N A306837 Number of unimodular n X n matrices with elements {0, 1}.
%C A306837 An integer matrix is unimodular if its determinant is -1 or +1.
%H A306837 S. E. Thornton, <a href="http://www.bohemianmatrices.com/cpdb/unstructured/unstructured_0_1">Properties of the Bohemian family of n x n matrices with population {0, 1}</a>, Characteristic Polynomial Database.
%Y A306837 Number of different values taken by the determinant is in A089472.
%Y A306837 Maximum determinant is in A003432.
%Y A306837 A363862 gives equivalence classes up to row and column permutation.
%K A306837 nonn,more,hard
%O A306837 1,2
%A A306837 _Steven E. Thornton_, Mar 12 2019
%E A306837 a(7) and a(8) from _Brendan McKay_, Jun 25 2023