A129044 - OEIS

%I #3 Mar 30 2012 16:50:41

%S 0,1,2,8,36,185,1050,6421,40623,261828,1701370,11098331,72534862,

%T 474641785

%N Number of n-node triangulations of the projective plane N_1 in which every node has degree >= 4.

%D G. Ringel, Wie man die geschlossenen nichtorientierbaren Flaechen in moeglichst wenig Dreiecke zerlegen kann, Math. Ann. 130 (1955), 317-326.

%H Thom Sulanke, <a href="http://hep.physics.indiana.edu/~tsulanke/graphs/surftri/">Generating triangulations of surfaces (surftri)</a>, (also subpages).

%K nonn

%O 5,3

%A _N. J. A. Sloane_, May 12 2007