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 A191966 #26 Mar 21 2023 14:15:49
%S A191966 1,1,1,12,15,900,6615,90720,1995840,1360800,197920800,359251200,
%T A191966 1297296000,7264857600,119870150400,2615348736000,29640619008000,
%U A191966 533531142144000,101370917007360000,101370917007360000,425757851430912000,3325168819675422720000
%N A191966 Number of n X n symmetric (0,1) matrices that achieve the record mentioned in A191965.
%C A191966 Number of labeled squarefree graphs on n nodes with A006855(n) edges. - _Max Alekseyev_, Jan 29 2022
%H A191966 Max Alekseyev, <a href="/A191966/b191966.txt">Table of n, a(n) for n = 1..37</a>
%o A191966 (Sage) a191966 = lambda n: sum( factorial(n) // g.automorphism_group(return_group=False, order=True) for g in graphs.nauty_geng(options=f'-c -f {n} {oeis(6855)(n)}:0') ) # _Max Alekseyev_, Jan 29 2022
%Y A191966 Labeled version of A335820. Rightmost values in A352472.
%Y A191966 Cf. A006786, A006855, A077269, A191965, A300756.
%K A191966 nonn
%O A191966 1,4
%A A191966 _R. H. Hardin_ and _N. J. A. Sloane_, Jun 18 2011
%E A191966 a(11)-a(21) from _Max Alekseyev_, Jan 29 2022
%E A191966 Corrected and extended to a(37) by _Max Alekseyev_, Mar 12 2023