A107185 Primes of the form 4x^2 + 19y^2.
19, 23, 83, 163, 271, 367, 419, 479, 491, 503, 571, 619, 919, 947, 967, 1031, 1051, 1151, 1187, 1259, 1327, 1499, 1543, 1607, 1619, 1783, 1831, 2087, 2239, 2287, 2399, 2411, 2531, 2591, 2671, 2699, 3083, 3307, 3323, 3391, 3407, 3467, 3847
Offset: 1
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)
Programs
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Mathematica
QuadPrimes2[4, 0, 19, 10000] (* see A106856 *)
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PARI
list(lim)=my(v=List(),w,t); for(x=0, sqrtint(lim\4), w=4*x^2; for(y=1, sqrtint((lim-w)\19), if(isprime(t=w+19*y^2), listput(v,t)))); Set(v) \\ Charles R Greathouse IV, Feb 10 2017
Comments