A042274 Numerators of continued fraction convergents to sqrt(663).

25, 26, 77, 103, 5227, 5330, 15887, 21217, 1076737, 1097954, 3272645, 4370599, 221802595, 226173194, 674148983, 900322177, 45690257833, 46590580010, 138871417853, 185461997863, 9411971311003, 9597433308866

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, 0, 0, 206, 0, 0, 0, -1).

Formula

G.f.: (25 +26*x +77*x^2 +103*x^3 +77*x^4 -26*x^5 +25*x^6 -x^7)/(1 -206*x^4 +x^8). - Vincenzo Librandi, Nov 20 2013

a(n) = 206*a(n-4) - a(n-8). - Vincenzo Librandi, Nov 18 2013

Mathematica

Numerator[Convergents[Sqrt[663], 30]] (* Harvey P. Dale, Aug 21 2011 *)
CoefficientList[Series[(25 + 26 x + 77 x^2 + 103 x^3 + 77 x^4 - 26 x^5 + 25 x^6 - x^7)/(1 - 206 x^4 + x^8), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 20 2013 *)

Prog

(Magma) I:=[25, 26, 77, 103, 5227, 5330, 15887, 21217]; [n le 8 select I[n] else 206*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Nov 18 2013

Crossrefs

Cf. A042275.

Sequence in context: A042252 A042250 A042272 * A042270 A042268 A042266

Adjacent sequences: A042271 A042272 A042273 * A042275 A042276 A042277

Keyword

nonn,cofr,frac,easy

Author

N. J. A. Sloane.

Status

approved