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.
%I A142956 #15 Feb 18 2022 17:28:54
%S A142956 5,17,61,73,101,137,149,157,197,229,233,277,313,349,353,389,397,457,
%T A142956 461,541,557,577,593,613,617,653,701,709,733,757,761,769,809,821,853,
%U A142956 881,929,937,997,1013,1033,1049,1061,1069,1109,1201,1213,1217,1277,1289
%N A142956 Primes of the form -3*x^2 + 4*x*y + 5*y^2 (as well as of the form 6*x^2 + 10*x*y + y^2).
%C A142956 Discriminant = 76. Class = 2. Binary quadratic forms a*x^2 + b*x*y + c*y^2 have discriminant d = b^2 - 4ac.
%D A142956 Z. I. Borevich and I. R. Shafarevich, Number Theory. Academic Press, NY, 1966.
%H A142956 N. J. A. Sloane et al., <a href="/wiki/Binary_Quadratic_Forms_and_OEIS">Binary Quadratic Forms and OEIS</a>: Index to related sequences, programs, references. OEIS wiki, June 2014.
%H A142956 D. B. Zagier, <a href="https://doi.org/10.1007/978-3-642-61829-1">Zetafunktionen und quadratische Körper</a>, Springer, 1981.
%e A142956 a(2) = 17 because we can write 17 = -3*3^2 + 4*3*2 + 5*2^2 (or 17 = 6*1^2 + 10*1*1 + 1^2).
%t A142956 Reap[For[p = 2, p < 2000, p = NextPrime[p], If[FindInstance[p == -3*x^2 + 4*x*y + 5*y^2, {x, y}, Integers, 1] =!= {}, Print[p]; Sow[p]]]][[2, 1]] (* _Jean-François Alcover_, Oct 25 2016 *)
%Y A142956 Cf. A142955 (d=76). A038872 (d=5). A038873 (d=8). A068228, A141123 (d=12). A038883 (d=13). A038889 (d=17). A141111, A141112 (d=65).
%K A142956 nonn
%O A142956 1,1
%A A142956 Laura Caballero Fernandez, Lourdes Calvo Moguer, Maria Josefa Cano Marquez, Oscar Jesus Falcon Ganfornina and Sergio Garrido Morales (laucabfer(AT)alum.us.es), Jul 14 2008
%E A142956 More terms from _Colin Barker_, Apr 05 2015
%E A142956 Edited by _M. F. Hasler_, Feb 18 2022