OFFSET
1,1
COMMENTS
Different from A342038, here a nontrivial multiple of p is required.
a(n) exists for all n: from the formula in A307437 we know a((p-1)/2*p^e) = p^(e+1) if p is an odd prime and (p-1)*p^e+1 is composite. For fixed p, there exist infinitely many e such that (p-1)*p^e+1 is composite.
Conjecture: a(n) >= prime(n)-1 for all n.
FORMULA
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Jianing Song, Feb 26 2021
STATUS
approved