%I #28 Nov 19 2023 21:16:08
%S 13,29,41,53,58,61,73,74,85,89,97,106,109,113,125,130,137,149,157,173,
%T 181,185,193,202,218,229,233,241,250,265,269,274,277,281,293,298,313,
%U 314,317,337,338,346,349,353,365,370,373,389,394,397,409,421,425,433
%N Numbers k such that the continued fraction for sqrt(k) has odd period, omitting those values of k of the form m^2+1.
%C p^2 - n*q^2 = -1 is solvable for integers p and q.
%C A031396 is the union of this sequence with A002522.
%H Colin Barker, <a href="/A240950/b240950.txt">Table of n, a(n) for n = 1..1000</a>
%e sqrt(13) = [3;1,1,1,1,6].
%e sqrt(29) = [5;2,1,1,2,10].
%Y Cf. A002522, A003814, A031396.
%K nonn
%O 1,1
%A _Takao Ito_, Aug 04 2014
%E More terms from _Colin Barker_, Dec 18 2014