

A129115


Number of unrooted unlabeled not necessarily connected triangular maps on a compact closed oriented surface with 2n faces (and thus 3n edges).


1



1, 3, 17, 124, 1618, 33564, 956263, 33736198, 1402665692, 66902717187, 3596481426812, 215049652739982, 14154852098315796, 1016911004448831247, 79174846391508487198, 6640511488761139957873, 596865894849670793348763
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,2


COMMENTS

Equivalently, the number of pair of permutations (sigma,tau) up to simultaneous conjugacy on a set of size 6*n with sigma^3=tau^2=1 with no fixed point.


LINKS



CROSSREFS

Unconnected version of A129114. Unrooted, unconnected version of A062980.


KEYWORD

nonn


AUTHOR



STATUS

approved



