%I #2 Mar 30 2012 17:26:31

%S 7,37,163,709,877,46447,67867,81517,118687,238639,292147,331207,

%T 430999,497737,548347,628063,1120429,1412539,1462897,1655089,1680919,

%U 1955809,2642257,3205897,3358063,3394813,3781087,4654813,4715419,4745869

%N Primes p of the form p=n^2+3n+9 such that q=p^2+3p+9 is also prime.

%C Intersection of A175283 and A005471.

%t Reap[Do[If[PrimeQ[p=n^2+3n+9]&&PrimeQ[q=p^2+3p+9],Sow[p]],{n,-1,10^4}]][[2,1]]

%Y Cf. A005471, A175281-3.

%K nonn

%O 1,1

%A _Zak Seidov_, Mar 21 2010