A042524 Numerators of continued fraction convergents to sqrt(791).

28, 225, 12628, 101249, 5682572, 45561825, 2557144772, 20502720001, 1150709464828, 9226178438625, 517816702027828, 4151759794661249, 233016365203057772, 1868282681419123425, 104856846524673969572

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (0, 450, 0, -1).

Formula

G.f.: (28 +225*x +28*x^2 -x^3)/(1 -450*x^2 +x^4). - Vincenzo Librandi, Nov 26 2013

a(n) = 450*a(n-2) - a(n-4). - Vincenzo Librandi, Nov 26 2013

Mathematica

Numerator[Convergents[Sqrt[791], 30]] (* or *) CoefficientList[Series[(28 + 225 x + 28 x^2 - x^3)/(1 - 450 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 25 2013 *)

Prog

(Magma) I:=[28, 225, 12628, 101249]; [n le 4 select I[n] else 450*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Nov 26 2013

Crossrefs

Cf. A042525.

Sequence in context: A133071 A339137 A135180 * A125365 A126523 A115224

Adjacent sequences: A042521 A042522 A042523 * A042525 A042526 A042527

Keyword

nonn,cofr,frac,easy

Author

N. J. A. Sloane.

Status

approved