The OEIS is supported by the many generous donors to the OEIS Foundation.
%I N1533 #6 Jun 12 2012 00:15:03
%S 5,7,8,9,10,11,12,12,13,13,14,15,15,16,16,16,17,17,18,18,19,19,19,20,
%T 20,20,21,21,21,22,22,22,23,23,23,24,24,24,24,25,25,25,25,26,26,26,27,
%U 27,27,27,28,28,28,28,28,29,29,29,29,30,30,30,30,31,31,31,31,31,32,32
%N a(0)=5, thereafter a(n) = chromatic number (or Heawood number) Chi(n) of surface of genus n.
%C This is what A000934 would have looked like if the four-color conjecture had turned out to be false.
%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%Y Cf. A000934.
%K nonn
%O 0,1
%A _N. J. A. Sloane_, Jun 12 2012