A333894 Number of unlabeled loopless multigraphs with n nodes of degree 3 or less.

1, 1, 4, 8, 26, 60, 184, 488, 1509, 4468, 14494, 47228, 163584, 580489, 2155219, 8245929, 32708045, 133615420, 562518913, 2432472970, 10794454457, 49060744260, 228113422904, 1083584062308, 5253168117841, 25964917671574, 130732997627332, 669989546176410, 3492408687398352

Offset

0,3

Links

Table of n, a(n) for n=0..28.

Formula

Euler transform of A243391.

Crossrefs

Column k=3 of A333893.

Cf. A243391.

Sequence in context: A074188 A126733 A297695 * A218079 A012982 A012952

Adjacent sequences: A333891 A333892 A333893 * A333895 A333896 A333897

Keyword

nonn

Author

Andrew Howroyd, Apr 08 2020

Status

approved