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.

A336792 Values of odd prime numbers, D, for incrementally largest values of minimal positive y satisfying the equation x^2 - D*y^2 = -2.

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%I A336792 #22 Feb 14 2021 01:38:15
%S A336792 3,19,43,67,139,211,331,379,571,739,859,1051,1291,1531,1579,1699,2011,
%T A336792 2731,3019,3259,3691,3931,5419,5659,5779,6211,6379,6451,8779,9619,
%U A336792 10651,16699,17851,18379,21739,25939,32971,42331,42571,44851,50131,53299,55819,56611,60811,61051,73459,76651,90619,90931
%N A336792 Values of odd prime numbers, D, for incrementally largest values of minimal positive y satisfying the equation x^2 - D*y^2 = -2.
%C A336792 For the corresponding y values see A336793.
%C A336792 For solutions of this Diophantine equation it is sufficient to consider the odd primes p(n) := A007520(n), for n >= 1, the primes 3 (mod 8). Also prime 2 has the fundamental solution (x, y) = (0, 1). If there is a solution for p(n) then there is only one infinite family of solutions because there is only one representative parallel primitive binary quadratic form for Discriminant Disc = 4*p(n) and representation k = -2. Only proper solutions can occur. The conjecture is that each p(n) leads to solutions. For the fundamental solutions (with prime 2) see A339881 and A339882. - _Wolfdieter Lang_, Dec 22 2020
%H A336792 Christine Patterson, <a href="/A336792/a336792.txt">Sage Program</a>
%e A336792 For D=3, the least positive y for which x^2-D*y^2=-2 has a solution is 1. The next prime, D, for which x^2-D*y^2=-2 has a solution is 11, but the smallest positive y in this case is also 1, which is equal to the previous record y. So 11 is not a term.
%e A336792 The next prime, D, after 11 for which x^2-D*y^2=-2 has a solution is 19 and the least positive y for which it has a solution is y=3, which is larger than 1, so it is a new record y value. So 19 is a term of this sequence and 3 is a term of A336793.
%Y A336792 Cf. A033316 (analogous for x^2-D*y^2=1), A336790 (similar sequence for x's), A336793.
%K A336792 nonn
%O A336792 1,1
%A A336792 _Christine Patterson_, Oct 14 2020