A193266 - OEIS

%I #14 Nov 11 2014 11:01:10

%S 2,8,10,20,38,40,58,70,98,100,110,160,170,188,190,220,308,350,380,538,

%T 568,598,628,640,680,688,698,740,748,818,850,968,1010,1028,1048,1088,

%U 1190,1228,1300,1378,1420,1430,1448,1528,1540,1550,1568,1580,1730,1738

%N Numbers n such that n + 3 and n^2 + 9 are primes.

%e 2 + 3 = 5 and  4 + 9 = 13 are primes,

%e 8 + 3 = 11 and  64 + 9 = 73 are primes.

%t Select[Prime[Range[3,300]]-3,PrimeQ[#^2+9]&] (* _Harvey P. Dale_, Nov 11 2014 *)

%o (PARI)  {a=3;forstep(n=2,2000,2,if(isprime(n+a)&&isprime(n^2+a^2),print1(n",")))}

%Y Cf. A070689, A192794.

%K nonn

%O 1,1

%A _Zak Seidov_, Dec 19 2012