%I A142955
%S A142955 2,3,19,31,59,67,71,79,103,107,127,151,167,179,211,223,227,307,331,379,
%T A142955 383,431,439,487,523,547,563,599,607,659,683,743,751,787,811,827,839,
%U A142955 863,887,907,911,971,983,991
%N A142955 Primes of the form 3*x^2+4*x*y-5*y^2 (as well as of the form 3*x^2+10*x*y+2*y^2).
%C A142955 Discriminant = 76. Class = 2. Binary quadratic forms a*x^2+b*x*y+c*y^2 
               have discriminant d=b^2-4ac and gcd(a,b,c)=1.
%D A142955 Borevich and Shafaewich, Number Theory.
%D A142955 D. B. Zagier, Zetafunktionen und quadratische Koerper.
%e A142955 a(4)=31 because we can write 31=3*3^2+4*3*2-5*2^2 (or 31=3*1^2+10*1*2+2*2^2).
%Y A142955 Cf. A142956 (d=76). A038872 (d=5). A141131 (d=8). A141122, A141123 (d=12). 
               A038883 (d=13). A038889 (d=17). A141111, A141112 (d=65).
%Y A142955 Sequence in context: A140555 A058912 A040145 this_sequence A088790 A135958 
               A163665
%Y A142955 Adjacent sequences: A142952 A142953 A142954 this_sequence A142956 A142957 
               A142958
%K A142955 nonn
%O A142955 1,1
%A A142955 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