A228521 x-values in the solution to the Pell equation x^2 - 29*y^2 = -1.

70, 1372210, 26898060350, 527255777608490, 10335267725783560630, 202591917433553577860770, 3971206755197249507443252910, 77843594612784567411349065681050, 1525890137628596335200014878036689190, 29910498399952150749806124227926115821330

Offset

1,1

Links

Colin Barker, Table of n, a(n) for n = 1..200

Index entries for linear recurrences with constant coefficients, signature (19602,-1).

Formula

a(n) = 19602*a(n-1)-a(n-2).

G.f.: 70*x*(x+1) / (x^2-19602*x+1).

Mathematica

LinearRecurrence[{19602, -1}, {70, 1372210}, 20] (* Harvey P. Dale, Nov 18 2024 *)

Prog

(PARI) Vec(70*x*(x+1)/(x^2-19602*x+1) + O(x^100))

Crossrefs

Cf. A228522 gives the corresponding y-values.

Sequence in context: A172659 A172759 A172829 * A222746 A066789 A103165

Adjacent sequences: A228518 A228519 A228520 * A228522 A228523 A228524

Keyword

nonn,easy

Author

Colin Barker, Aug 24 2013

Status

approved