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%I #19 Aug 30 2019 03:44:11
%S 0,0,8,800,282528,367387328,1761545807424,31759604694829568,
%T 2200205489188051284480,595216852658907342647518208,
%U 635231932478914399659212336569344,2690533983413127566229805840755659706368,45382894419701545228622064475653706685702246400,3054532231410772852023213016232868881612380314752933888
%N Number of strongly connected labeled digraphs on n nodes with an odd number of edges.
%H 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 a(n) = (A003030(n)-(n-1)!)/2.
%t 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 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 a[n_] := (c[n] - (n - 1)!)/2;
%t Table[a[n], {n, 1, 15}] (* _Jean-François Alcover_, Aug 30 2019, after _Vaclav Kotesovec_ in A003030 *)
%Y Cf. A003030, A054944.
%K nonn,easy
%O 1,3
%A _N. J. A. Sloane_, May 24 2000
%E More terms from _Vladeta Jovovic_, Jul 15 2000
%E More terms from _Jean-François Alcover_, Aug 30 2019
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