#68Exact endpoint
Irrationality becomes one cofinal divisibility question
QuestionIs ∑n ≥ 2 1/(n! − 1) irrational?
The original series problem is reduced without loss to an integer event that can be attacked directly.
EvidenceLean checked exact equivalence
Still openForce failures of m dividing the strict successor beyond every cutoff.
Classical factorial radix context; source specific formal synthesis; no priority claim.