A129419 Number of isomorphism classes of connected 5-regular loopless multigraphs of order 2n.

1, 4, 49, 1689, 187392, 46738368, 20446754006, 14021056991357, 14141140657400321, 20047531681346319557, 38567298550226625579671, 97861817259606311572409609, 319914449561753621623849929222, 1320949150506412557504787822889933, 6773751604973857152218372443743552754

Offset

1,2

Comments

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

Links

Table of n, a(n) for n=1..15.

Brendan McKay and Adolfo Piperno, Nauty and Traces

Formula

Inverse Euler transform of A129420. - Andrew Howroyd, Mar 17 2020

Prog

(nauty/bash) geng -c -d1 $[2*$n] -q | multig -r5 -u # Natan Arie Consigli, Dec 20 2019

Crossrefs

Column k=5 of A328682.

Cf. A129420, A129430, A000421, A129417, A129421, A129423, A129425, A328682.

Sequence in context: A191301 A336805 A029991 * A212130 A049503 A159593

Adjacent sequences: A129416 A129417 A129418 * A129420 A129421 A129422

Keyword

nonn

Author

Brendan McKay, Apr 15 2007

Extensions

a(8)-a(15) from Andrew Howroyd, Mar 21 2020

Status

approved