A006426 Number of rooted toroidal maps with 3 vertices and n faces and no isthmuses.

10, 340, 5846, 71372, 706068, 6052840, 46759630, 333746556, 2238411692, 14277544216, 87376309020, 516495616120, 2964332933800, 16586670357200, 90782049175614, 487329793111260, 2571575908919740, 13364166071956280, 68507393061864020, 346874109053120616

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

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

A diagonal of A343092.

Extensions

Name clarified and terms a(10) and beyond from Andrew Howroyd, Apr 05 2021