A107156 Primes of the form 2x^2 + 25y^2.

2, 43, 97, 227, 233, 257, 313, 353, 467, 563, 617, 643, 673, 787, 907, 947, 1193, 1283, 1297, 1483, 1777, 1873, 1907, 2027, 2083, 2153, 2203, 2267, 2273, 2377, 2417, 2617, 2683, 2803, 2963, 3067, 3083, 3187, 3217, 3313, 3593, 3673, 3907

Offset

1,1

Comments

Discriminant = -200. 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[2, 0, 25, 10000] (* see A106856 *)

Prog

(PARI) list(lim)=my(v=List(), w, t); for(x=1, sqrtint(lim\2), w=2*x^2; for(y=0, sqrtint((lim-w)\25), if(isprime(t=w+25*y^2), listput(v, t)))); Set(v) \\ Charles R Greathouse IV, Feb 09 2017

Crossrefs

Sequence in context: A090194 A107200 A079823 * A062582 A073594 A349927

Adjacent sequences: A107153 A107154 A107155 * A107157 A107158 A107159

Keyword

nonn,easy

Author

T. D. Noe, May 13 2005

Status

approved