%I M4237 #32 Apr 05 2018 22:50:57
%S 0,0,1,6,40,320,2946,29364,309558,3365108,37246245,416751008,
%T 4696232371,53186743416,604690121555,6896534910612,78867385697513,
%U 904046279771682,10384916465797240,119522063788612992,1378014272286250059
%N Number of unsensed genus 1 maps with n edges.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H Evgeniy Krasko and Alexander Omelchenko, <a href="https://arxiv.org/abs/1712.10139">Enumeration of Unsensed Orientable Maps on Surfaces of a Given Genus</a>, arXiv:1712.10139 [math.CO], 2017.
%H Timothy R. Walsh, <a href="http://www.info2.uqam.ca/~walsh_t/papers/GENERATING NONISOMORPHIC.pdf">Space-efficient generation of nonisomorphic maps and hypermaps</a>
%H Timothy R. Walsh, <a href="http://dx.doi.org/10.1137/0604018">Generating nonisomorphic maps without storing them</a>, SIAM J. Algebraic Discrete Methods 4 (1983), no. 2, 161-178.
%H T. R. Walsh, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL18/Walsh/walsh3.html">Space-Efficient Generation of Nonisomorphic Maps and Hypermaps</a>, J. Int. Seq. 18 (2015) # 15.4.3
%Y Cf. A006385, A214814, A214815, A214816.
%K nonn
%O 0,4
%A _N. J. A. Sloane_
%E a(12)-a(20) from _Evgeniy Krasko_, Sep 17 2017