
COMMENTS

a(n)=1 iff n+1 is prime. For n>1 n+a(n) is odd (for n>1 a(n) is odd iff n is even). a(11) is greater than 7000. a(m) for m=12,13,14,15,16,17 and 18 are 1, 54, 17, 2, 1, 1080, 1. 5^7954 + 7954 is a 5560digit probable prime.
a(11) is greater than 8651.  Robert G. Wilson v, May 24 2004
a(11) is greater than 20165, so every prime of the form 11^m + m has more than 21000 digits.  Farideh Firoozbakht, Jun 10 2004
a(11) is greater than 80000.  T. D. Noe, Mar 07 2007
a(11) is greater than 190000.  T. D. Noe, Jul 31 2008


MATHEMATICA

a[n_]:=(For[m=1, !PrimeQ[n^m+m], m++ ]; m); Do[Print[a[n]], {n, 0, 10}]
