A129421 Number of isomorphism classes of connected 6-regular loopless multigraphs of order n.

0, 1, 1, 6, 15, 120, 933, 13303, 252207, 6450828, 205475039, 7936493756, 363639228194, 19476976825809, 1205115679461426, 85288127619421544, 6845235025444882069, 618411485467843477405, 62471139399366989007575, 7014991719815977343879171

Offset: 1

Author

Brendan McKay, Apr 15 2007

Keywords

• nonn

Comments

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

Links

• Brendan McKay and Adolfo Piperno, Nauty and Traces

Crossrefs

Column k=6 of A328682.

Cf. A129422, A129432, A000421, A129417, A129419, A129423, A129425, A328682.

Programs

nauty

geng -c -d1 ${n} -q | multig -r6 -u # Natan Arie Consigli, Jun 05 2017

Formula

Inverse Euler transform of A129422. - Andrew Howroyd, Mar 17 2020

Extensions

a(1)=0 prepended and a(14)-a(20) from Andrew Howroyd, Mar 17 2020