A129417 Number of isomorphism classes of connected 4-regular loopless multigraphs of order n.

1, 0, 1, 1, 3, 6, 19, 50, 204, 832, 4330, 25227, 171886, 1303725, 10959478, 100230117, 989280132, 10455393155, 117701173970, 1405165683359, 17726785643045, 235585551038117, 3289367315407521, 48136794098893837, 736721822918719557, 11768987500655142988

Offset: 0

Author

Brendan McKay, Apr 15 2007

Keywords

• nonn

Comments

Initial terms computed using software at http://users.cecs.anu.edu.au/~bdm/nauty/

Obtained from A129418 by an inverse Euler transform. - R. J. Mathar, Mar 09 2019

Links

• Brendan McKay and Adolfo Piperno, Nauty and Traces

Crossrefs

Column k=4 of A328682.

Cf. A129418, A085549, A000421, A129419, A129421, A129423, A129425, A328682.

Programs

nauty

geng -c -d1 ${n} -q | multig -r4 -u # Natan Arie Consigli, Jun 05 2017

Extensions

a(0)-a(1) prepended by Natan Arie Consigli, Jun 05 2017

a(18)-a(25) from Andrew Howroyd, Mar 17 2020