1,1

a(1) = 7 = A111668(1). Conjectures: (1) This is a subsequence of the safe primes (A005385), (2) lim{n --> oo}(a(n+1)/a(n)) = 2.

Cf. A111668, A005385 (safe primes).

Sequence in context: A082496 A107133 A079138 this_sequence A140111 A118072 A076855

Adjacent sequences: A111668 A111669 A111670 this_sequence A111672 A111673 A111674

nonn

Rick L. Shepherd (rshepherd2(AT)hotmail.com), Aug 15 2005