%I M0560 #8 Mar 30 2012 16:45:02

%S 1,2,3,4,6,8,11,15,21,28,39,53,99,137,186

%N Number of regions in certain maps.

%D Gustavus J. Simmons, The ochromatic number of planar graphs, pp. 295-316 of F. Harary and J. S. Maybee, editors, Graphs and Applications. Wiley, NY, 1985.

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%K nonn

%O 1,2

%A _N. J. A. Sloane_.