Egyptian fractions with denominators from sequences closed under doubling.
D. Eppstein.
J. Integer Sequences 24: 21.8.8, 2021.
arXiv:2109.12217.
We prove that if a set of positive integers includes multiples of all integers, and is closed under multiplication by two, then its reciprocals can form Egyptian fractions for every rational number up to the sum of reciprocals of the set.
See also my previous paper "Ten algorithms for Egyptian fractions", and my blog posts "Egyptian fractions with practical denominators" (on which this paper was based) and "Which integer sequences form denominators of Egyptian fractions?" (announcing the paper).