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 A153636 Primes of the form 4x^3 + 27y^2, with x>0. 3

%I

%S 31,59,283,499,743,1327,1399,1579,1823,2687,3271,3299,3371,3559,3767,

%T 4027,4243,4567,4639,5323,5351,6079,8059,8123,8563,9463,9851,9887,

%U 10111,10247,11003,11119,11399,11939,12163,13127,13163,14243,14783,15907

%N Primes of the form 4x^3 + 27y^2, with x>0.

%H T. D. Noe, <a href="/A153636/b153636.txt">Table of n, a(n) for n = 1..1000</a>

%t nn=10^5; Select[Sort[Flatten[Table[4a^3+27b^2, {b,Sqrt[nn/27]}, {a,((nn-27b^2)/4)^(1/3)}]]], PrimeQ[ # ] &]

%o (PARI) is(p)=for(b=1,sqrtint(max(0,p-4)\27),my(t=p-27*b^2);if(t%4==0&&ispower(t/4,3),return(isprime(p))));0 \\ _Charles R Greathouse IV_, Jun 06 2013

%Y A153635 (positive or negative x).

%Y Cf. A154291.

%K nonn

%O 1,1

%A _T. D. Noe_, Dec 29 2008

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Last modified March 20 21:07 EDT 2023. Contains 361391 sequences. (Running on oeis4.)