A042858 Numerators of continued fraction convergents to sqrt(960).

30, 31, 1890, 1921, 117150, 119071, 7261410, 7380481, 450090270, 457470751, 27898335330, 28355806081, 1729246700190, 1757602506271, 107185397076450, 108942999582721, 6643765372039710, 6752708371622431, 411806267669385570, 418558976041008001, 25525344830129865630

Offset

0,1

Links

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

Index entries for linear recurrences with constant coefficients, signature (0,62,0,-1).

Formula

G.f.: (30 + 31*x + 30*x^2 - x^3)/(1 - 62*x^2 + x^4). - Vincenzo Librandi, Dec 08 2013

a(n) = 62*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 08 2013

Mathematica

Numerator[Convergents[Sqrt[960], 30]] (* Vincenzo Librandi, Dec 07 2013 *)
CoefficientList[Series[(30 + 31 x + 30 x^2 - x^3)/(1 - 62 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 08 2013 *)

Prog

(Magma) I:=[ 30, 31, 1890, 1921]; [n le 4 select I[n] else 62*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 08 2013

Crossrefs

Cf. A042859.

Sequence in context: A268337 A042856 A042857 * A175514 A043584 A043776

Adjacent sequences: A042855 A042856 A042857 * A042859 A042860 A042861

Keyword

nonn,cofr,frac,easy

Author

N. J. A. Sloane

Extensions

More terms from Vincenzo Librandi, Dec 08 2013

Status

approved