cp's OEIS Frontend

A243654 Nonnegative numbers represented by the indefinite quadratic form 3x^2+5xy-3y^2, of discriminant 61.

%I A243654 #21 May 05 2023 16:23:12
%S A243654 0,1,3,4,5,9,12,13,15,16,19,20,25,27,36,39,41,45,47,48,49,52,57,60,61,
%T A243654 64,65,73,75,76,80,81,83,95,97,100,103,107,108,109,113,117,121,123,
%U A243654 125,127,131,135,137,141,144,147,149,156,163,164,167,169,171,179,180,183,188,192,195,196,197,199
%N A243654 Nonnegative numbers represented by the indefinite quadratic form 3x^2+5xy-3y^2, of discriminant 61.
%C A243654 Also, nonnegative numbers represented by the indefinite quadratic form x^2-61y^2, of discriminant 244. The corresponding reduced form is x^2+14xy-12y^2.
%C A243654 Also 12*a(n) has the form z^2 - 61*y^2, where z = 6*x+5*y. [_Bruno Berselli_, Jun 20 2014]
%H A243654 Robert Israel, <a href="/A243654/b243654.txt">Table of n, a(n) for n = 1..10000</a>
%H A243654 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)
%p A243654 select(t -> nops([isolve(x^2-61*y^2=t)])>0,[$0..200]); # _Robert Israel_, Jun 11 2014
%o A243654 (C++) // Computed using Will Jagy's C++ program Conway_Positive_All (see A243655 for the source code).
%Y A243654 For primes see A141215.
%K A243654 nonn
%O A243654 1,3
%A A243654 _N. J. A. Sloane_, Jun 10 2014