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A003028 Number of n-node digraphs with a source.
(Formerly M3157)
3
1, 3, 51, 3614, 991930, 1051469032, 4366988803688, 71895397383029040, 4719082081411731363408, 1237678715644664931691596416, 1297992266840866792981316221144960 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

V. Jovovic and G. Kilibarda, Enumeration of labeled initially-finally connected digraphs, Scientific review, Serbian Scientific Society, 19-20 (1996) 237-247.

R. W. Robinson, Counting labeled acyclic digraphs, pp. 239-273 of F. Harary, editor, New Directions in the Theory of Graphs. Academic Press, NY, 1973.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=1..11.

V. Jovovic and G. Kilibarda, Enumeration of labeled quasi-initially connected digraphs, Discrete Math., 224 (2000), 151-163.

CROSSREFS

Sequence in context: A172434 A210676 A105639 * A069343 A084882 A275798

Adjacent sequences:  A003025 A003026 A003027 * A003029 A003030 A003031

KEYWORD

nonn,easy,nice

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Corrected and extended by Vladeta Jovovic, Goran Kilibarda

STATUS

approved

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Last modified August 9 12:14 EDT 2020. Contains 336323 sequences. (Running on oeis4.)