A129056 - OEIS

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

%S 0,34,3864,87396,818072,4611407,18933909

%N Number of n-node triangulations of the nonorientable surface N_4 in which every node has degree >= 6.

%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 8,2

%A _N. J. A. Sloane_, May 13 2007