A185194 Number of unlabeled digraphs on n vertices such that every vertex has outdegree 4.

0, 0, 0, 0, 1, 40, 35317, 56150820, 111359017198, 278086517599356, 877760741062694898, 3482578978170418753715, 17204168691253789080138981, 104690934973509839187285618311, 776311587313178356520412354767734, 6942595716239018207126337605515965388

Offset: 1

Author

Nathaniel Johnston, Feb 08 2012

Keywords

• nonn

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=4 of A329228.

Cf. A001373, A129524, A185193, A185303.

Extensions

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