A006437 Number of tree-rooted toroidal maps with 3 faces and n vertices and without isthmuses. (Formerly M5342)

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

Offset

1,1

References

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

Links

Table of n, a(n) for n=1..9.

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.

Sequence in context: A093757 A163022 A271031 * A067643 A285170 A017786

Adjacent sequences: A006434 A006435 A006436 * A006438 A006439 A006440

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

Name clarified by Andrew Howroyd, Apr 04 2021

Status

approved