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 A054927 #24 May 08 2019 10:43:54 %S A054927 1,0,0,1,4,17,122,1512,32692,1332942,105327842,15931236010, %T A054927 4514847754466,2400986640234092,2424697785383015323, %U A054927 4646743375611622382082,16785578201380816581985232,114710315501226850209685442155 %N A054927 Number of connected unlabeled graphs having n nodes and ceiling(n(n-1)/4) edges such that the complement is also connected. %C A054927 These graphs are called "median graphs" by Liskovets, but that name is more commonly used for the graphs counted in A292623. - _Brendan McKay_, Apr 14 2019 %H A054927 V. A. Liskovets, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL3/LISK/Derseq.html">Some easily derivable sequences</a>, J. Integer Sequences, 3 (2000), #00.2.2. %F A054927 a(n) = A001437(n)+A054926(n)-A000717(n). %K A054927 nonn,more %O A054927 1,5 %A A054927 _N. J. A. Sloane_, May 24 2000 %E A054927 Name changed by _Brendan McKay_, Apr 14 2019 %E A054927 3 more terms by lookup in the 3 seqs of the formula. - _R. J. Mathar_, May 08 2019