A107155 Primes of the form x^2 + 49y^2.

53, 113, 149, 193, 197, 277, 317, 373, 421, 449, 457, 541, 557, 809, 821, 953, 1009, 1117, 1229, 1289, 1409, 1481, 1493, 1549, 1597, 1709, 1789, 1801, 1873, 1877, 1901, 1933, 2053, 2153, 2221, 2293, 2377, 2381, 2389, 2417, 2437, 2521, 2549

Offset

1,1

Comments

Discriminant = -196. 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, 49, 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)\49), if(isprime(t=w+49*y^2), listput(v, t)))); Set(v) \\ Charles R Greathouse IV, Feb 09 2017

Crossrefs

Sequence in context: A141975 A142663 A229960 * A139504 A142798 A140025

Adjacent sequences: A107152 A107153 A107154 * A107156 A107157 A107158

Keyword

nonn,easy

Author

T. D. Noe, May 13 2005

Status

approved