1,2

Subsequence of A070325, which itself is a subsequence of A070689, which itself is a subsequence of A006093.

Table of n, a(n) for n=1..34.

a(3) = 690 = A070689(32) = A070325(11) = A006093(125).

(MAGMA) [n: n in [0..7000000]| IsPrime(1+n) and IsPrime(1+n^2) and IsPrime(1+n^4) and IsPrime(1+n^16)]; // Vincenzo Librandi, Apr 11 2011

Sequence in context: A079195 A120123 A140014 * A209364 A106301 A127623

Adjacent sequences: A188695 A188696 A188697 * A188699 A188700 A188701

nonn

Zak Seidov, Apr 09 2011

a(1) = 1 prepended by Vincenzo Librandi, Apr 11 2011

approved