A006427 - OEIS

A006427

Number of rooted toroidal maps with 4 vertices and n faces and no isthmuses.
(Formerly M5105)

20, 1071, 26320, 431739, 5494896, 58677420, 550712668, 4681144391, 36786186216, 271221867098, 1896796135920, 12688048319278, 81709791432384, 509222462694582, 3083998029716868, 18213177504318335, 105186858991413976, 595499805083872458, 3311524095424508480

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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..19.

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

A diagonal of A343092.

Sequence in context: A128476 A160132 A138915 * A072962 A224125 A324416

Adjacent sequences: A006424 A006425 A006426 * A006428 A006429 A006430