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%I #14 Jul 10 2019 11:34:49
%S 378,216041742,123476065138818,70571263317093720342,
%T 40334158693601634671687178,23052504391353119813669652619422,
%U 13175382254784845233371524284127523858,7530231623112168370599341126488007078134182
%N x-values in the solution to the Pell equation x^2 - 85*y^2 = -1.
%C All terms are multiples of 378.
%H Colin Barker, <a href="/A228554/b228554.txt">Table of n, a(n) for n = 1..150</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (571538,-1).
%F a(n) = 571538*a(n-1)-a(n-2).
%F G.f.: 378*x*(x+1) / (x^2-571538*x+1).
%t LinearRecurrence[{571538,-1},{378,216041742},20] (* _Harvey P. Dale_, Jul 10 2019 *)
%o (PARI) Vec(378*x*(x+1)/(x^2-571538*x+1) + O(x^30))
%Y Cf. A228555 gives the corresponding y-values.
%K nonn,easy
%O 1,1
%A _Colin Barker_, Aug 25 2013
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