

A003026


Number of nnode labeled acyclic digraphs with 2 outpoints.
(Formerly M4666)


6



1, 9, 198, 10710, 1384335, 416990763, 286992935964, 444374705175516, 1528973599758889005, 11573608032229769067465, 191141381932394665770442818, 6839625961762363728765713227698
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OFFSET

2,2


REFERENCES

R. W. Robinson, Counting labeled acyclic digraphs, pp. 239273 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).


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PROG



CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



