A185193 Number of unlabeled digraphs on n vertices such that every vertex has outdegree 3.

0, 0, 0, 1, 13, 1499, 257290, 56150820, 14971125930, 4829990898461, 1864386642498918, 851204815909786099, 454661054439318678263, 281270600132956104641972, 199701092658236514672384967, 161392692052798327047616107614, 147373164027242947672475065773269

Offset

1,5

Links

Andrew Howroyd, Table of n, a(n) for n = 1..50

L. Travis, [math/9811127] Graphical Enumeration: A Species-Theoretic Approach

Crossrefs

Column k=3 of A329228.

Cf. A001373, A129524, A185194, A185303.

Sequence in context: A201357 A220551 A185073 * A066457 A203515 A166929

Adjacent sequences: A185190 A185191 A185192 * A185194 A185195 A185196

Keyword

nonn

Author

Nathaniel Johnston, Feb 08 2012

Extensions

Terms a(10) and beyond from Andrew Howroyd, Nov 08 2019

Status

approved