A237423 Primes p such that prime(prime(p^2)) - 2 is also prime.

13, 17, 167, 179, 211, 223, 337, 373, 541, 661, 743, 751, 1063, 1129, 1217, 1607, 1697, 1741, 1913, 2017, 2039, 2083, 2293, 2389, 2447, 2459, 2543, 2677, 2693, 2711, 2851, 2909, 3083, 3191, 3209, 3259, 3571, 3889, 3917

Offset: 1

Author

K. D. Bajpai, Feb 07 2014

Keywords

• nonn
• base
• less

Examples

			13 is prime and appears in the sequence because  prime(prime(13^2)) - 2  = 8009 which is also prime.
17 is prime and appears in the sequence because  prime(prime(17^2)) - 2  = 16139 which is also prime.
		

Links

• K. D. Bajpai, Table of n, a(n) for n = 1..155

Crossrefs

Cf. A000040, A234695, A236119, A236687, A236688, A237283

Programs

Maple

KD := proc() local a,b;  a:=ithprime(n);  b:=ithprime(ithprime(a^2))-2;  if isprime (b) then RETURN (a); fi;  end: seq(KD(), n=1..500);

Mathematica

p[n_] := PrimeQ[Prime[Prime[n^2]] - 2]; n = 0; Do[If[p[Prime[m]], n = n + 1; Print[n, " ", Prime[m]]], {m, 1000}] (* Bajpai *)
Select[Prime[Range[105]], PrimeQ[Prime[Prime[#^2]] - 2] &] (* Wouter Meeussen, Feb 09 2014 *)