A107153 Primes of the form 2x^2 + 23y^2.
2, 23, 31, 41, 73, 151, 223, 239, 257, 311, 449, 577, 593, 599, 601, 607, 647, 673, 719, 823, 863, 929, 967, 991, 1087, 1129, 1153, 1223, 1289, 1297, 1327, 1481, 1543, 1559, 1823, 1871, 1889, 1913, 2063, 2129, 2143, 2377, 2441, 2473, 2657, 2663
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[2, 0, 23, 10000] (* see A106856 *)
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PARI
list(lim)=my(v=List(),w,t); for(x=0, sqrtint(lim\2), w=2*x^2; for(y=0, sqrtint((lim-w)\23), if(isprime(t=w+23*y^2), listput(v,t)))); Set(v) \\ Charles R Greathouse IV, Feb 09 2017
Comments