A006437 Number of tree-rooted toroidal maps with 3 faces and n vertices and without isthmuses.

70, 2330, 32130, 271285, 1655800, 7997850, 32332170, 113568455, 355905030

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• more

References

• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• T. R. S. Walsh and A. B. Lehman, Counting rooted maps by genus. III: Nonseparable maps, J. Combinatorial Theory Ser. B 18 (1975), 222-259.

Crossrefs

Cf. A006436.

Extensions

Name clarified by Andrew Howroyd, Apr 04 2021