A107211 Primes of the form 2x^2 + 47y^2.

2, 47, 79, 97, 431, 439, 521, 761, 769, 929, 1193, 1223, 1297, 1303, 1399, 1481, 1567, 1753, 1823, 1847, 2143, 2311, 2503, 2591, 2633, 2753, 2857, 3089, 3271, 3361, 3623, 3761, 3767, 3919, 4007, 4049, 4217, 4481, 4703, 5407, 5503, 5689

Offset

1,1

Comments

Discriminant = -376. 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, 47, 10000] (* see A106856 *)

Prog

(PARI) list(lim)=my(v=List(), w, t); for(x=0, sqrtint(lim\2), w=2*x^2; for(y=0, sqrtint((lim-w)\47), if(isprime(t=w+47*y^2), listput(v, t)))); Set(v) \\ Charles R Greathouse IV, Feb 10 2017

Crossrefs

Sequence in context: A139839 A248862 A118104 * A069548 A065044 A142313

Adjacent sequences: A107208 A107209 A107210 * A107212 A107213 A107214

Keyword

nonn,easy

Author

T. D. Noe, May 13 2005

Status

approved