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 A054944 #19 Aug 30 2019 03:44:01
%S A054944 1,1,10,806,282552,367387448,1761545808144,31759604694834608,
%T A054944 2200205489188051324800,595216852658907342647881088,
%U A054944 635231932478914399659212340198144,2690533983413127566229805840755699623168,45382894419701545228622064475653706686181248000,3054532231410772852023213016232868881612380320979954688
%N A054944 Number of strongly connected labeled digraphs on n nodes with an even number of edges.
%H A054944 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 A054944 a(n) = (A003030(n)+(n-1)!)/2.
%t A054944 b[n_] := b[n] = If[n == 1, 1, 2^(n*(n - 1)) - Sum[Binomial[n, j]*2^((n - 1)*(n - j))*b[j], {j, 1, n - 1}]];
%t A054944 c[1] = 1; c[n_] := c[n] = b[n] + Sum[Binomial[n - 1, j - 1]*b[n - j]*c[j], {j, 1, n - 1}];
%t A054944 a[n_] := (c[n] + (n - 1)!)/2;
%t A054944 Table[a[n], {n, 1, 15}] (* _Jean-François Alcover_, Aug 30 2019, after _Vaclav Kotesovec_ in A003030 *)
%Y A054944 Cf. A054945.
%K A054944 nonn,easy
%O A054944 1,3
%A A054944 _N. J. A. Sloane_, May 24 2000
%E A054944 More terms from _Vladeta Jovovic_, Jul 15 2000
%E A054944 More terms from _Jean-François Alcover_, Aug 30 2019