A238185 Primes p such that prime(prime(p^2)) + 2 is also prime.

2, 23, 97, 163, 463, 491, 557, 659, 677, 977, 1033, 1151, 1187, 1429, 1439, 1511, 1579, 1663, 1933, 2111, 2113, 2141, 2381, 2969, 3301, 3491, 3803, 3929, 4201, 4421, 4447, 4513, 4547, 4789, 5039, 5273, 5281, 5303, 5309, 5449, 5669, 5741, 5939, 5981, 6053

Offset: 1

Author

K. D. Bajpai, Feb 19 2014

Keywords

• nonn
• less

Examples

			23 is in the sequence because 23 is prime and prime(prime(23^2)) + 2 = 35803 is also prime.
97 is in the sequence because 97 is prime and prime(prime(97^2)) + 2 = 1269643 is also prime.
		

Links

• K. D. Bajpai, Table of n, a(n) for n = 1..163

Crossrefs

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

Programs

Maple

KD := proc() local a,b,d; a:=ithprime(n); b:=ithprime(ithprime(a^2))+2; if isprime (b) then RETURN (a);fi; end: seq(KD(), n=1..300);

Mathematica

n=0; Do[If[PrimeQ[Prime[Prime[Prime[k]^2]]+2],n=n+1; Print[n," ",Prime[k]]], {k,1,5000}]
Select[Prime[Range[800]],PrimeQ[Prime[Prime[#^2]]+2]&] (* Harvey P. Dale, Dec 19 2014 *)