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A107159
Primes of the form 4x^2 + 13y^2.
3
13, 17, 29, 113, 157, 181, 269, 313, 337, 373, 389, 521, 601, 641, 653, 673, 701, 797, 809, 1069, 1109, 1117, 1153, 1213, 1249, 1453, 1481, 1609, 1613, 1621, 1637, 1777, 1933, 1949, 1973, 2053, 2081, 2089, 2129, 2213, 2237, 2297, 2341, 2357, 2393
OFFSET
1,1
COMMENTS
Discriminant = -208. 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[4, 0, 13, 10000] (* see A106856 *)
PROG
(PARI) list(lim)=my(v=List(), w, t); for(x=0, sqrtint(lim\4), w=4*x^2; for(y=1, sqrtint((lim-w)\13), if(isprime(t=w+13*y^2), listput(v, t)))); Set(v) \\ Charles R Greathouse IV, Feb 09 2017
CROSSREFS
Sequence in context: A283358 A033210 A274506 * A138375 A180526 A161401
KEYWORD
nonn,easy
AUTHOR
T. D. Noe, May 13 2005
STATUS
approved