A176245 - OEIS

%I #4 May 01 2013 21:06:47

%S 3,37,160001

%N Primes of the form A174881(k)+1.

%C There are no primes of the form A174881(k)-1.

%C There are no further terms through ((40*(40+1))^40) + 1 = 52330005981567385600000001 * 7498996269037701079813541255115132352481561590213553612395236504891175431182405289081378432614400.

%C Contribution from _Farideh Firoozbakht_, Apr 22 2010: (Start)

%C Each term is of the form (4^n+2^n)^2^n+1. Next term (if it exists) is

%C greater than (4^15+2^15)^2^15, so it has more than 295924 digits. (End)

%e a(1) = (1^1)*((1+1)^1) + 1 = 2 + 1 = 3 is prime.

%e a(2) = (2^2)*((2+1)^2) + 1 = 36 + 1 = 37 is prime.

%e a(3) = (4^4)*((4+1)^4) + 1 = 160000 + 1 = 160001 is prime.

%Y Cf. A000040, A000169, A000312, A174881.

%K bref,more,nonn

%O 1,1

%A _Jonathan Vos Post_, Apr 12 2010

%E Edited by Farideh Firoozbakht and _N. J. A. Sloane_, Apr 18 2010