Two terms with known prime divisors adding to a power: REVISED with APPENDICES

Reese Scott, Robert Styer

Let $c$ be a positive odd integer and $R$ a set of $n$ primes coprime with $c$. We consider equations $X+Y=c^z$ in three integer unknowns $X$, $Y$, $z$, where $z>0$, $Y > X >…