Formal target: Corpus.OEIS93456.conjecture
Conjecture: There are finitely many numbers such that $a(n)$ is not $\equiv 0 \pmod{a(n-1)}$.
Exact formal statement
Set.Finite.{0}
(Set.ofPred.{0} fun n =>
And (LT.lt.{0} 1 n) (Not (Dvd.dvd.{0} (Corpus.OEIS93456.a (HSub.hSub.{0, 0, 0} n 1)) (Corpus.OEIS93456.a n))))This target is a formal statement, not a proof of the problem.
Environment availability: available.