OFFSET
1,1
EXAMPLE
a(2)=6 as: gcd(prime(2)+6,2+prime(6)) = gcd(3+6,2+13) = gcd(9,15) = 3 and gcd(prime(2)+k,2+prime(k))=1 for 2<k<6.
PROG
(PARI) a(n) = my(k=n+1); while(gcd(prime(n)+k, n+prime(k)) == 1, k++); k; \\ Michel Marcus, Feb 05 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jan 28 2002
STATUS
approved