A107205 Primes of the form 2x^2 + 45y^2.

2, 47, 53, 173, 383, 503, 557, 647, 743, 797, 983, 1013, 1103, 1223, 1367, 1373, 1613, 1637, 1847, 1973, 2087, 2207, 2213, 2237, 2333, 2357, 2447, 2477, 2543, 2693, 2927, 3407, 3557, 3677, 3767, 3863, 3917, 4013, 4127, 4157, 4253, 4463

Offset

1,1

Comments

Discriminant = -360. 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, 45, 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)\45), if(isprime(t=w+45*y^2), listput(v, t)))); Set(v) \\ Charles R Greathouse IV, Feb 10 2017

Crossrefs

Sequence in context: A124690 A195877 A141579 * A139839 A248862 A118104

Adjacent sequences: A107202 A107203 A107204 * A107206 A107207 A107208

Keyword

nonn,easy

Author

T. D. Noe, May 13 2005

Status

approved