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Number of rooted toroidal maps with 2 vertices and n faces and no isthmuses.
(Formerly M3700)
1

%I M3700 #10 Apr 05 2021 11:56:15

%S 4,79,900,7885,59080,398846,2499096,14805705,83969600,459868530,

%T 2447439384,12718070274,64766697520,324156347260,1598200903280,

%U 7776728909121,37404399901296,178060831286890,839857764202520,3928581810398630,18239060530882224,84101317494787684

%N Number of rooted toroidal maps with 2 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(11) and beyond from _Andrew Howroyd_, Apr 05 2021