%I M3166 #12 Apr 06 2021 21:12:43
%S 0,3,60,650,5352,37681,239752,1421226,7996160,43219990,226309800,
%T 1154900708,5769562736,28312118565,136830224464,652656300122,
%U 3077631550512,14367512295274,66478236840680,305161336656876,1390869368495728,6298727501142218,28358908010334960
%N Number of tree-rooted planar maps with 3 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 Andrew Howroyd, <a href="/A006432/b006432.txt">Table of n, a(n) for n = 1..100</a>
%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.
%F a(n) seems to be divisible by n+1. - _Ralf Stephan_, Sep 01 2003
%Y A diagonal of A342987.
%K nonn
%O 1,2
%A _N. J. A. Sloane_
%E Name clarified and terms a(13) and beyond from _Andrew Howroyd_, Apr 06 2021