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y-values in the solution to the Pell equation x^2 - 85*y^2 = -1.
2

%I #13 Nov 29 2017 17:58:13

%S 41,23433017,13392859670105,7654528230109038473,

%T 4374853755566666771111369,2500395165741407064797340577049,

%U 1429070852233137457244575771954319993,816768296741122520872908940486430799582185

%N y-values in the solution to the Pell equation x^2 - 85*y^2 = -1.

%C All terms are multiples of 41.

%H Colin Barker, <a href="/A228555/b228555.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.: -41*x*(x-1) / (x^2-571538*x+1).

%t LinearRecurrence[{571538,-1},{41,23433017},20] (* _Harvey P. Dale_, Nov 29 2017 *)

%o (PARI) Vec(-41*x*(x-1)/(x^2-571538*x+1) + O(x^30))

%Y Cf. A228554 gives the corresponding x-values.

%K nonn,easy

%O 1,1

%A _Colin Barker_, Aug 25 2013