Wiki
Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
Updated
Claims
1972_06_01_ruzsa: Ruzsa constructed a set with at most a constant times N over log N elements up to N such that every large integer is a power of two plus an element of the set, answering Problem 221 yes.
2001_04_01_ruzsa: Ruzsa constructed a set with asymptotically N over log base two of N elements up to N such that every large integer is a power of two plus an element of the set, the best possible count for Problem 221.
Linked from (1)
Graph