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Numbers k such that 3*k^2 + 64 is prime.
1

%I #13 Mar 14 2020 03:28:33

%S 1,5,7,9,13,15,27,33,35,41,47,51,57,63,65,69,71,77,79,83,85,89,91,103,

%T 113,117,121,139,141,147,155,175,181,187,189,191,197,201,215,219,223,

%U 225,239,243,247,251,253,259,261,265,281,293,299

%N Numbers k such that 3*k^2 + 64 is prime.

%H Daniel Starodubtsev, <a href="/A111083/b111083.txt">Table of n, a(n) for n = 1..10000</a>

%e If k=113 then (3*k^2) + 64 = 38371 (prime).

%t Select[Range[300], PrimeQ[3*#^2 + 64] &] (* _Stefan Steinerberger_, Feb 26 2006 *)

%o (PARI) is(n)=isprime(3*n^2+64) \\ _Charles R Greathouse IV_, Jun 13 2017

%Y Cf. A111068, A111069.

%K nonn,easy

%O 1,2

%A _Parthasarathy Nambi_, Oct 11 2005

%E More terms from _Stefan Steinerberger_, Feb 26 2006