  Resolving a conjecture of Zhi-Wei Sun, we prove that every rational number
can be represented as a sum of distinct unit fractions whose denominators are
practical numbers. The same method applies to allowed denominators that are
closed under multiplication by two and include a multiple of every positive
integer, including the odious numbers, evil numbers, Hardy-Ramanujan numbers,
Jordan-Polya numbers, and fibbinary numbers.
