What degree angle are the corners of a regular tetrahedron?
Regular number integers "i", "j", and "k". Such a number is a divisor of formula_1. The regular numbers are also called 5-smooth, indicating that their greatest prime factor is at most 5. The first few regular numbers are Several other sequences at OEIS have definitions involving 5-smooth numbers. Although the regular numbers appear dense within the range from 1 to 60, they are quite sparse among the larger integers. A regular number "n" = 2·3·5 is less than or equal to "N" if and only if the point ("i","j","k") belongs to the tetrahedron bounded by the coordinate planes and the plane as
Tetrahedron wide applications in practical applications in computational fluid dynamics, aerodynamics, electromagnetic fields, civil engineering, chemical engineering, naval architecture and engineering, and related fields. The tetrahedron shape is seen in nature in covalently bonded molecules. All sp-hybridized atoms are surrounded by atoms (or lone electron pairs) at the four corners of a tetrahedron. For instance in a methane molecule () or an ammonium ion (), four hydrogen atoms surround a central carbon or nitrogen atom with tetrahedral symmetry. For this reason, one of the leading journals in organic chemistry is called "Tetrahedron". The central angle between any two vertices of a