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

31, 59, 283, 499, 743, 1327, 1399, 1579, 1823, 2687, 3271, 3299, 3371, 3559, 3767, 4027, 4243, 4567, 4639, 5323, 5351, 6079, 8059, 8123, 8563, 9463, 9851, 9887, 10111, 10247, 11003, 11119, 11399, 11939, 12163, 13127, 13163, 14243, 14783, 15907

Offset

1,1

Links

T. D. Noe, Table of n, a(n) for n = 1..1000

Mathematica

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

Prog

(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

Crossrefs

A153635 (positive or negative x).

Cf. A154291.

Sequence in context: A043953 A327447 A139954 * A109840 A108293 A316349

Adjacent sequences: A153633 A153634 A153635 * A153637 A153638 A153639

Keyword

nonn

Author

T. D. Noe, Dec 29 2008

Status

approved