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Number of rooted toroidal maps with 4 vertices and n faces and no isthmuses.
(Formerly M5105)
1

%I M5105 #10 Apr 05 2021 11:45:31

%S 20,1071,26320,431739,5494896,58677420,550712668,4681144391,

%T 36786186216,271221867098,1896796135920,12688048319278,81709791432384,

%U 509222462694582,3083998029716868,18213177504318335,105186858991413976,595499805083872458,3311524095424508480

%N Number of rooted toroidal maps with 4 vertices and n faces and no isthmuses.

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

%H T. R. S. Walsh and A. B. Lehman, <a href="http://dx.doi.org/10.1016/0095-8956(75)90050-7">Counting rooted maps by genus. III: Nonseparable maps</a>, J. Combinatorial Theory Ser. B 18 (1975), 222-259.

%Y A diagonal of A343092.

%K nonn

%O 1,1

%A _N. J. A. Sloane_

%E Name clarified and terms a(9) and beyond from _Andrew Howroyd_, Apr 05 2021