Guy's Conjecture
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). See also Crossing Number (Graph)
References
Sloane, N. J. A. SequenceA000241/M2772in ``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.
- Extensions Calculus
- Extent
- Exterior
- Exterior Algebra
- Exterior Angle Bisector
- Exterior Angle Theorem
- Exterior Derivative
- Exterior Dimension
- Exterior Product
- Exterior Snowflake
- Extrapolation
- Extra Strong Lucas Pseudoprime
- Extremal Coloring
- Extremal Graph
- Extremals
- Extreme and Mean Ratio
- Extreme Value Distribution
- Extreme Value Theorem
- Extremum
- Extremum Test
- Extrinsic Curvature
- Fabry Imbedding
- Face
- Facet
- Faceting