A129422 Number of isomorphism classes of 6-regular loopless multigraphs of order n.

0, 1, 1, 7, 16, 128, 955, 13467, 253373, 6466074, 205749149, 7943313377, 363853255012, 19485170158346, 1205488841884007, 85308028236495340, 6846462326434510551, 618498122199399056707, 62478078728492272712838, 7015617595855429187696753

Offset

1,4

Comments

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

Links

Table of n, a(n) for n=1..20.

Formula

Euler transform of A129421. - Andrew Howroyd, Mar 14 2020

Crossrefs

Column k=6 of A333330.

Cf. A129421, A129433, A129416, A129418, A129420, A129424, A129426.

Sequence in context: A351531 A181777 A332573 * A184062 A101122 A090535

Adjacent sequences: A129419 A129420 A129421 * A129423 A129424 A129425

Keyword

nonn

Author

Brendan McKay, Apr 15 2007

Extensions

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

Status

approved