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%I #16 Jul 31 2021 02:15:32
%S 1,3,54,3804,1022320,1065957628,4389587378792,72020744942708040,
%T 4721708591209396542528,1237892622263984613044109216,
%U 1298060581376190776821670648395840
%N Number of quasi-initially connected digraphs with n labeled nodes.
%C We say that a node v of a digraph is a quasi-source iff for every other node u there exists directed path from u to v or from v to u. A digraph with at least one quasi-source is called quasi-initially connected.
%H Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a049/A049414.java">Java program</a> (github)
%H V. Jovovic and G. Kilibarda, <a href="http://dx.doi.org/10.1016/S0012-365X(00)00112-6">Enumeration of labeled quasi-initially connected digraphs</a>, Discrete Math., 224 (2000), 151-163.
%F The recurrence formulas are too long to be presented here.
%Y Cf. A003027, A003028, A003029, A003030.
%Y Row sums of A057272.
%K nonn
%O 1,2
%A _Vladeta Jovovic_, Goran Kilibarda