distinct positive odd numbers. Solutions to this equation are known to always exist for the case in which . See also List of sums of reciprocals Notes References . . . . . . See in particular the "Small numerators" section . . . . . . . . . . . . . . . . Reprinted with additional annotations in . . . . . . Conjectures Unsolved problems in number theory Egyptian fractions Diophantine equations Straus conjecture