OFFSET
1,1
FORMULA
Conjecture: a(n) > (1/2) * prime(n-1)#.
PROG
(PARI) a(n) = my(P=vecprod(primes(n)), p=1); while(!ispseudoprime(floor((P/p)+1)) || gcd(P, p)<>p, p=p+2); (P/p)+1;
CROSSREFS
KEYWORD
nonn
AUTHOR
Alain Rocchelli, Aug 16 2023
STATUS
approved