OFFSET
1,1
COMMENTS
Primes p such that p^2 + 2 = 3q, where q is prime, and p^2 - 2 is semiprime.
LINKS
K. D. Bajpai, Table of n, a(n) for n = 1..3670
EXAMPLE
a(1) = 11 is prime: 11^2 + 2 = 123 = 3 * 41 which is semiprime: 11^2 - 2 = 119 = 7 * 17 which is also semiprime.
a(2) = 17 is prime: 17^2 + 2 = 291 = 3 * 97 which is semiprime: 17^2 - 2 = 287 = 7 * 41 which is also semiprime.
MAPLE
MATHEMATICA
A242244 = {}; Do[p = Prime[n]; If[PrimeOmega[p^2 + 2] == 2 && PrimeOmega[p^2 - 2] == 2, AppendTo[A242244, p]], {n, 2000}]; A242244
Select[Prime[Range[600]], PrimeOmega[#^2+{2, -2}]=={2, 2}&] (* Harvey P. Dale, Apr 07 2018 *)
PROG
(PARI) is(n)=isprime(n) && isprime((n^2+2)\3) && bigomega(n^2-2)==2 \\ Charles R Greathouse IV, May 15 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
K. D. Bajpai, May 09 2014
STATUS
approved