Guy's conjecture, which has not yet been proven or disproven, states that the Crossing Number for a Complete Graph of order is

where is the Floor Function, which can be rewritten

The first few values are 0, 0, 0, 0, 1, 3, 9, 18, 36, 60, ... (Sloane's A000241).

**References**

Sloane, N. J. A. Sequence
A000241/M2772
in ``An On-Line Version of the Encyclopedia of Integer Sequences.''
http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S.
*The Encyclopedia of Integer Sequences.* San Diego: Academic Press, 1995.

© 1996-9

1999-05-25