A360868 Number of unlabeled connected loopless multigraphs with circuit rank n and degree >= 3 at each node.

0, 1, 4, 23, 172, 1848, 25684

Offset

1,3

Links

Table of n, a(n) for n=1..7.

Formula

a(n) = Sum_{k>=1} A360866(n + k - 1, k).

Crossrefs

Diagonal sums of A360866.

Cf. A360864, A360867, A360879.

Sequence in context: A317276 A113869 A084357 * A075729 A328006 A127131

Adjacent sequences: A360865 A360866 A360867 * A360869 A360870 A360871

Keyword

nonn,hard,more

Author

Andrew Howroyd, Feb 25 2023

Status

approved