A006436 Number of tree-rooted toroidal maps with 2 faces and n vertices and without isthmuses. (Formerly M4743)

10, 192, 1630, 8924, 36834, 124560, 362934, 941820, 2227368, 4881448, 889015725

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..11.

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. A006437.

Sequence in context: A356495 A244385 A134633 * A252974 A341503 A187652

Adjacent sequences: A006433 A006434 A006435 * A006437 A006438 A006439

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

Name clarified by Andrew Howroyd, Apr 04 2021

Status

approved