cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A106903 Primes of the form x^2+xy+13y^2, with x and y nonnegative.

This page as a plain text file.
%I A106903 #19 Jan 15 2016 12:24:42
%S A106903 13,19,43,67,103,127,151,157,223,229,271,307,331,349,373,409,421,433,
%T A106903 457,523,577,613,661,727,733,739,757,769,829,859,883,919,937,967,1021,
%U A106903 1063,1069,1087,1123,1171,1237,1249,1327,1381,1429,1447,1453,1471
%N A106903 Primes of the form x^2+xy+13y^2, with x and y nonnegative.
%C A106903 Discriminant=-51.
%C A106903 Differs from A106904 from a(20) = 523 on, A106904(20) = 463. Since x^2 + xy + y^2 = (x+y)^2 - (x+y)y + y^2, this sequence is a subsequence of A106904. - _M. F. Hasler_, Jan 15 2016
%H A106903 Vincenzo Librandi and Ray Chandler, <a href="/A106903/b106903.txt">Table of n, a(n) for n = 1..10000</a> [First 1000 terms from Vincenzo Librandi]
%H A106903 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)
%t A106903 QuadPrimes2[1, 1, 13, 10000] (* see A106856 *)
%o A106903 (PARI) select(p->isprime(p)&&(t=qfbsolve(Qfb(1,1,13),p))&&t[1]>=0,[1..1500]) \\ _M. F. Hasler_, Jan 15 2016
%K A106903 nonn,easy
%O A106903 1,1
%A A106903 _T. D. Noe_, May 09 2005