Erdős problem 469
Does the sum of the reciprocals of all primitive pseudoperfect numbers converge?
Sources
FormalConjectures/ErdosProblems/
469.lean
Retained formal statement
Let be the set of all such that with distinct proper divisors of , but this is not true for any with . Does: converge?
Yes: the sum converges. This was proved by Lewis [Le25], whose proof has been formalized in Lean.
True ↔ Summable fun n => 1 / ↑↑n