A226986 Primes p such that both prevprime(p^2) - 2 and nextprime(p^2) + 2 are also primes.

3, 251, 409, 647, 1031, 1669, 6469, 6679, 12043, 18313, 18517, 31583, 31643, 32957, 33479, 33529, 37783, 39733, 40163, 44071, 58441, 67189, 68279, 83009, 83117, 83423, 87671, 90481, 96001, 98479, 112951, 120011, 130211, 149939, 152297, 155663, 156227, 158293

Offset

1,1

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Mathematica

Select[Prime[Range[15000]], AllTrue[{NextPrime[#^2, -1]-2, NextPrime[ #^2]+2}, PrimeQ]&] (* Harvey P. Dale, Jun 12 2022 *)

Prog

(PARI) is(n)=isprime(precprime(n^2)-2) && isprime(nextprime(n^2)+2) && isprime(n) \\ Charles R Greathouse IV, Jun 25 2013

Crossrefs

Sequence in context: A318065 A349644 A124875 * A158351 A025418 A075901

Adjacent sequences: A226983 A226984 A226985 * A226987 A226988 A226989

Keyword

nonn

Author

Juri-Stepan Gerasimov, Jun 25 2013

Extensions

a(3)-a(34) from Giovanni Resta, Jun 13 2013

a(10) inserted by Charles R Greathouse IV, Jun 25 2013

Status

approved