OFFSET
1,1
REFERENCES
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.
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.
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.
FORMULA
For n >= 25, a(n) = floor(5n/3).
CROSSREFS
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Feb 07 2012
STATUS
approved