A132644 X-values of solutions to the equation X*(X + 1) - 13*Y^2 = 0.

0, 324, 421200, 546717924, 709639444800, 921111452633124, 1195601955878350800, 1551890417618646705924, 2014352566467047545939200, 2614628079383810095982376324, 3393785232687619037537578530000

Offset

0,2

Links

Table of n, a(n) for n=0..10.

Index entries for linear recurrences with constant coefficients, signature (1299,-1299,1).

Formula

a(n) = 1298*a(n-1) - a(n-2) + 648; a(0)=0, a(1)=324.

G.f.: -324*x*(x+1)/((x-1)*(x^2 - 1298*x + 1)). - Colin Barker, Oct 25 2012

Mathematica

CoefficientList[Series[-((324 x (1+x))/(-1+1299 x-1299 x^2+x^3)), {x, 0, 20}], x] (* or *) LinearRecurrence[{1299, -1299, 1}, {0, 324, 421200}, 20] (* Harvey P. Dale, Jul 24 2021 *)

Crossrefs

Cf. A007654.

Sequence in context: A298101 A209044 A209016 * A202635 A013763 A013887

Adjacent sequences: A132641 A132642 A132643 * A132645 A132646 A132647

Keyword

nonn,easy

Author

Mohamed Bouhamida, Nov 14 2007

Extensions

More terms from Paolo P. Lava, Oct 07 2008

Status

approved