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A232011 Numbers n such that (3n)^2 + 2 is prime. 2

%I

%S 1,3,5,7,11,13,15,19,27,33,35,37,39,41,49,57,73,75,79,81,83,85,91,99,

%T 101,103,107,115,117,121,123,125,129,139,141,143,147,149,151,159,167,

%U 171,183,185,187,191,201,203,217,225,227,233,237,251,259,269,273,279

%N Numbers n such that (3n)^2 + 2 is prime.

%C Corresponding values of such primes are in A056899(n) for n>2.

%C Supersequence of A126960 (primes p such that (3p)^2 + 2 is prime).

%H Jaroslav Krizek, <a href="/A232011/b232011.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = sqrt(A056899(n+2) - 2)/3 = A067201(n+2)/3.

%e 7 is in sequence because (3*7)^2 + 2 = 443 (prime).

%t Select[Range[279], PrimeQ[9 #^2 + 2] &] (* _T. D. Noe_, Nov 27 2013 *)

%o (PARI) is(n)=isprime(9*n^2+2) \\ _Charles R Greathouse IV_, Nov 25 2013

%Y Cf. A000040, A056899, A067201, A126960.

%K nonn

%O 1,2

%A _Jaroslav Krizek_, Nov 25 2013

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Last modified October 16 21:10 EDT 2019. Contains 328103 sequences. (Running on oeis4.)