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A139849 Primes of the form 10x^2 + 10xy + 13y^2. 1

%I

%S 13,73,97,157,313,397,433,577,733,853,937,997,1153,1237,1657,1693,

%T 1753,1777,1993,2113,2593,2617,2677,2833,2917,2953,3037,3253,3373,

%U 3433,3457,3517,3673,3793,3853,3877,4093,4177,4273,4297,4357,4513

%N Primes of the form 10x^2 + 10xy + 13y^2.

%C Discriminant = -420. See A139827 for more information.

%H Vincenzo Librandi and Ray Chandler, <a href="/A139849/b139849.txt">Table of n, a(n) for n = 1..10000</a> [First 1000 terms from Vincenzo Librandi]

%H N. J. A. Sloane et al., <a href="https://oeis.org/wiki/Binary_Quadratic_Forms_and_OEIS">Binary Quadratic Forms and OEIS</a> (Index to related sequences, programs, references)

%F The primes are congruent to {13, 73, 97, 157, 313, 397} (mod 420).

%t QuadPrimes2[10, -10, 13, 10000] (* see A106856 *)

%o (MAGMA) [ p: p in PrimesUpTo(6000) | p mod 420 in {13, 73, 97, 157, 313, 397}]; // _Vincenzo Librandi_, Jul 29 2012

%o (PARI) list(lim)=my(v=List(), s=[13, 73, 97, 157, 313, 397]); forprime(p=13, lim, if(setsearch(s, p%420), listput(v, p))); Vec(v) \\ _Charles R Greathouse IV_, Feb 10 2017

%K nonn,easy

%O 1,1

%A _T. D. Noe_, May 02 2008

%E Corrected and extended b-file - _Ray Chandler_, Jul 29 2014

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Last modified June 3 05:29 EDT 2020. Contains 334798 sequences. (Running on oeis4.)