A107193 Primes of the form x^2 + 81y^2.

97, 181, 277, 337, 349, 373, 613, 733, 757, 829, 853, 1129, 1213, 1237, 1297, 1321, 1549, 1657, 1693, 1753, 2017, 2029, 2089, 2137, 2221, 2281, 2521, 2917, 3037, 3049, 3181, 3217, 3229, 3433, 3469, 3541, 3697, 3877, 4093, 4177, 4549, 4597

Offset

1,1

Comments

Discriminant = -324. See A107132 for more information.

Links

Vincenzo Librandi and Ray Chandler, Table of n, a(n) for n = 1..10000 [First 1000 terms from Vincenzo Librandi]

N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)

Mathematica

QuadPrimes2[1, 0, 81, 10000] (* see A106856 *)

Prog

(PARI) list(lim)=my(v=List(), w, t); for(x=1, sqrtint(lim\1), w=x^2; for(y=1, sqrtint((lim-w)\81), if(isprime(t=w+81*y^2), listput(v, t)))); Set(v) \\ Charles R Greathouse IV, Feb 10 2017

Crossrefs

Sequence in context: A142094 A142212 A108655 * A256775 A364321 A142398

Adjacent sequences: A107190 A107191 A107192 * A107194 A107195 A107196

Keyword

nonn,easy

Author

T. D. Noe, May 13 2005

Status

approved