Brodsky, A.; Durocher, S.; and Gethner, E. "The Rectilinear Crossing Number of Is 62." 22 Sep 2000. http://arxiv.org/abs/cs/0009023.de Klerk, E.; Pasechnik, D. V.; and Schrijver, A. "Reduction of Symmetric Semidefinite Programs Using the Regular -Representation." Math Program.109, 613-624, 2007.de Klerk, E.; Maharry, J.; Pasechnik, D. V.; Richter, R. B.; Salazar, G. "Improved Bounds for the Crossing Numbers of and ." 2004. https://arxiv.org/pdf/math/0404142.pdf.Guy, R. K. "The Crossing Number of the Complete Graph." Bull. Malayan Math. Soc.7, 68-72, 1960.Guy, R. K. "Crossing Numbers of Graphs." In Graph Theory and Applications: Proceedings of the Conference at Western Michigan University, Kalamazoo, Mich., May 10-13, 1972 (Ed. Y. Alavi, D. R. Lick, and A. T. White). New York: Springer-Verlag, pp. 111-124, 1972.Harary, F. and Hill, A. "On the Number of Crossings in a Complete Graph." Proc. Edinburgh Math. Soc.13, 333-338, 1962/1963.Pan, S. and Richter, R. B. "The Crossing Number of is 100." J. Graph Th.56, 128-134, 2007.Sloane, N. J. A. Sequence A000241/M2772 in "The On-Line Encyclopedia of Integer Sequences."
is 
is the floor function, which can be rewritten 
, 2, ... are then given by 0, 0, 0, 0, 1, 3, 9, 18, 36, 60, 100, 150, 225, 315, 441, 588, ... (OEIS A000241). 
, a result extended to 
by Pan and Richter (2007). 
Is 62." 22 Sep 2000. 
-Representation." Math Program. 109, 613-624, 2007.de Klerk, E.; Maharry, J.; Pasechnik, D. V.; Richter, R. B.; Salazar, G. "Improved Bounds for the Crossing Numbers of 
and 
." 2004. 
is 100." J. Graph Th. 56, 128-134, 2007.Sloane, N. J. A. Sequence