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 A335776 #16 Aug 17 2020 13:34:53 %S A335776 0,0,4,42,436,5650,96544,2185610,65108236 %N A335776 Number of idempotent non-symmetric n X n (0,1)-matrices over the reals. %C A335776 Off diagonal entries of an idempotent symmetric n X n (0,1)-matrix must be zero. %F A335776 a(n) = A086922(n) - A000079(n). %e A335776 a(2) = 4 because [1,1] [0,1] [0,0] [1,0] %e A335776 [0,0], [0,1], [1,1], [1,0], are non-symmetric and idemponent. %Y A335776 Cf. A000079, A086922. %K A335776 nonn,more %O A335776 0,3 %A A335776 _Torlach Rush_, Jun 22 2020