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 A086875 #9 Sep 08 2022 08:45:11
%S A086875 1,21,1147,211965,143331811,366753209781
%N A086875 Sum of rank(M) over all n X n matrices over Z with all entries zero or one.
%C A086875 The unlikely-looking symbol "+:=" in the MAGMA code is in fact correct. - _N. J. A. Sloane_, Feb 02 2009
%F A086875 a(n) = Sum_{k=1..n} k * A064230(n,k). - _Alois P. Heinz_, Jun 18 2022
%o A086875 (Magma) for a in [1..5] do b := 0; for c in CartesianPower([0,1], a^2) do b +:= Rank(Matrix(a, a, [aa : aa in c])); end for; print b; end for;
%Y A086875 Cf. A064230.
%K A086875 hard,more,nonn
%O A086875 1,2
%A A086875 Tom Womack (tom(AT)womack.net), Aug 21 2003
%E A086875 a(6) from _Alois P. Heinz_, Jun 18 2022