%I #5 Mar 30 2012 16:52:09
%S 4,5,6,8,10,12,14,16,18,20,22,24,24,26,28,29,30,32,33,34,36,37,38,40
%N Achromatic number of K_4 X K_n.
%D Hornak, Mirko and Puntigan, Jozef, On the achromatic number of K_m X K_n. In Graphs and other combinatorial topics (Prague, 1982), 118-123, Teubner-Texte Math., 59, Teubner, Leipzig, 1983.
%D Hornak, Mirko and Pcola, Stefan, Achromatic number of K_5 X K_n for small n. Czechoslovak Math. J. 53 (128) (2003), no. 4, 963-988.
%D Hornak, Mirko and Pcola, Stefan, Achromatic number of K_5 X K_n for large n. Discrete Math. 234 (2001), no. 1-3, 159-169.
%F For n >= 25, a(n) = floor(5n/3).
%Y Cf. A206415.
%K nonn,more
%O 1,1
%A _N. J. A. Sloane_, Feb 07 2012