A042386 Numerators of continued fraction convergents to sqrt(720).

26, 27, 134, 161, 8506, 8667, 43174, 51841, 2738906, 2790747, 13901894, 16692641, 881919226, 898611867, 4476366694, 5374978561, 283975251866, 289350230427, 1441376173574, 1730726404001, 91439149181626

Offset

0,1

Links

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

Index entries for linear recurrences with constant coefficients, signature (0,0,0,322,0,0,0,-1).

Formula

G.f.: -(x^7-26*x^6+27*x^5-134*x^4-161*x^3-134*x^2-27*x-26)/((x^2-4*x-1)*(x^2+4*x-1)*(x^4+18*x^2+1)). [Colin Barker, Aug 09 2012]

Mathematica

Numerator/@Convergents[Sqrt[720], 50] (* Harvey P. Dale, Jul 08 2011 *)
CoefficientList[Series[- (x^7 - 26 x^6 + 27 x^5 - 134 x^4 - 161 x^3 - 134 x^2 - 27 x - 26)/((x^2 - 4 x - 1) (x^2 + 4 x - 1) (x^4 + 18 x^2 + 1)), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 27 2013 *)

Crossrefs

Cf. A042387.

Sequence in context: A042382 A042380 A042378 * A042384 A042388 A042390

Adjacent sequences: A042383 A042384 A042385 * A042387 A042388 A042389

Keyword

nonn,cofr,frac,easy

Author

N. J. A. Sloane.

Status

approved