A000840 Number of cubic bicolored graphs on n unlabeled nodes admitting an automorphism exchanging the colors.

0, 0, 1, 1, 2, 5, 12, 31, 90, 285, 938, 3285, 11983, 45390, 177803, 718390, 2986407, 12749364, 55802982, 250068732, 1145923828, 5363795830, 25620207380, 124767647097, 618983876918, 3126035142910, 16060182735947, 83883575376862, 445164927249466, 2399098651337048

Offset

1,5

Links

Table of n, a(n) for n=1..30.

Crossrefs

Column k=3 of A333159.

Cf. A000512, A000843, A004066, A008325.

Sequence in context: A045633 A090826 A132441 * A362635 A232215 A265265

Adjacent sequences: A000837 A000838 A000839 * A000841 A000842 A000843

Keyword

nonn

Author

Brendan McKay and Eric Rogoyski

Extensions

a(11)-a(30) from Andrew Howroyd, Mar 10 2020

Status

approved