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

1,1

Links

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

Example

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.

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 *)

Crossrefs

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

Sequence in context: A245331 A270868 A239186 * A053999 A357739 A131176

Adjacent sequences: A238182 A238183 A238184 * A238186 A238187 A238188

Keyword

nonn,less

Author

K. D. Bajpai, Feb 19 2014

Status

approved