A219895 Number of directed 3-regular graphs on n nodes without directed 2-cycles.

3, 26, 1547, 146487, 16018987, 1985766270, 278601715904

Offset

7,1

Links

Table of n, a(n) for n=7..13.

Gunnar Brinkmann, Generating regular directed graphs, Discrete Math., 313 (2012), 1-7.

Crossrefs

Cf. A096368, A219889, A219890, A219891, A219892, A219893, A219894.

Sequence in context: A174811 A214808 A378063 * A088730 A058956 A010257

Adjacent sequences: A219892 A219893 A219894 * A219896 A219897 A219898

Keyword

nonn,more

Author

N. J. A. Sloane, Nov 30 2012

Status

approved