A107218 Primes of the form 4x^2 + 25y^2.

29, 41, 61, 89, 229, 241, 281, 349, 421, 509, 601, 641, 661, 701, 709, 769, 809, 821, 881, 1009, 1049, 1109, 1181, 1201, 1229, 1249, 1289, 1301, 1321, 1381, 1409, 1481, 1549, 1669, 1709, 1789, 1801, 1901, 2029, 2069, 2089, 2141, 2161, 2221, 2281

Offset

1,1

Comments

Discriminant = -400. 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, 25, 10000] (* see A106856 *)

Prog

(PARI) list(lim)=my(v=List(), w, t); for(x=1, sqrtint(lim\4), w=4*x^2; for(y=1, sqrtint((lim-w)\25), if(isprime(t=w+25*y^2), listput(v, t)))); Set(v) \\ Charles R Greathouse IV, Feb 10 2017

Crossrefs

Sequence in context: A080899 A216815 A157141 * A346145 A058900 A137226

Adjacent sequences: A107215 A107216 A107217 * A107219 A107220 A107221

Keyword

nonn,easy

Author

T. D. Noe, May 13 2005

Status

approved