This is a good number to use. The full table is: http://en.wikipedia.org/wiki/Random_close_pack#For_spheres http://en.wikipedia.org/wiki/Random_close_pack#For

This is a good number to use. The full table is: http://en.wikipedia.org/wiki/Random_close_pack#For_spheres http://en.wikipedia.org/wiki/Random_close_pack#For_spheres IIRC, there's a passage in Conway and Sloane's comprehensive review of sphere-packing (the same Sloane as EIS, http://oeis.org/ http://oeis.org/) http://www.amazon.com/gp/product/0387985859/ref=dp_proddesc_1?ie=UTF8&n=283155 http://www.amazon.com/gp/product/0387985859/ref=dp_proddesc_... that says "much of our effort in this book is to find a packing, in arbitrary spaces, that is as efficient as the simple tetrahedral packing is in R^3".