Erdős Problem 44: Let N ≥ 1 and A ⊆ {1,…,N} be a Sidon set. Is it true that, for any ε > 0, there exist M = M(ε) and B ⊆ {N+1,…,M} such that A ∪ B ⊆ {1,…,M} is a Sidon set of size at least (1−ε)M^{1/2}?

How a contribution reaches this record

Seven steps, in four places.

1. 1

   Read the sources and their formal declarations.

   Public
2. 2

   Work on it, wherever you work.

   Your machine
3. 3

   Keep an Approach and its Attempts here.

   Needs an account
4. 4

   Attach evidence by its content root.

   Needs an account
5. 5

   Prepare an unsigned Submission draft.

   Needs an account
6. 6

   Sign it with your own key.

   Your machine
7. 7

   The Repository decides.

   The Repository