

A049414


Number of quasiinitially connected digraphs with n labeled nodes.


3



1, 3, 54, 3804, 1022320, 1065957628, 4389587378792, 72020744942708040, 4721708591209396542528, 1237892622263984613044109216, 1298060581376190776821670648395840
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OFFSET

1,2


COMMENTS

We say that a node v of a digraph is a quasisource 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 quasisource is called quasiinitially connected.


LINKS

Table of n, a(n) for n=1..11.
V. Jovovic and G. Kilibarda, Enumeration of labeled quasiinitially connected digraphs, Discrete Math., 224 (2000), 151163.


FORMULA

The recurrence formulas are too long to be presented here.


CROSSREFS

Cf. A003027, A003028, A003029, A003030.
Row sums of A057272.
Sequence in context: A091796 A171213 A006025 * A003027 A054545 A158103
Adjacent sequences: A049411 A049412 A049413 * A049415 A049416 A049417


KEYWORD

nonn


AUTHOR

Vladeta Jovovic, Goran Kilibarda


STATUS

approved



