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A049531 Number of digraphs with a source and a sink on n unlabeled nodes. 2
1, 2, 11, 173, 8675 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

V. Jovovic, G. Kilibarda, Enumeration of labeled initially-finally connected digraphs, Scientific review, Serbian Scientific Society, 19-20 (1996), p. 246.

LINKS

Table of n, a(n) for n=1..5.

CROSSREFS

Cf. A049524, A003085, A035512, A003088, A051421.

Sequence in context: A121231 A122527 A039747 * A031508 A202140 A011806

Adjacent sequences:  A049528 A049529 A049530 * A049532 A049533 A049534

KEYWORD

hard,nonn,nice

AUTHOR

Vladeta Jovovic, Goran Kilibarda

STATUS

approved

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Last modified June 20 17:27 EDT 2019. Contains 324234 sequences. (Running on oeis4.)