A042895 Denominators of continued fraction convergents to sqrt(979).

1, 3, 7, 38, 45, 218, 263, 1533, 3329, 11520, 717569, 2164227, 5046023, 27394342, 32440365, 157155802, 189596167, 1105136637, 2399869441, 8304744960, 517294056961, 1560186915843, 3637667888647, 19748526359078, 23386194247725, 113293303349978, 136679497597703

Offset

0,2

Links

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

Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 720898, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).

Formula

G.f.: -(x^18 - 3*x^17 + 7*x^16 - 38*x^15 + 45*x^14 - 218*x^13 + 263*x^12 - 1533*x^11 + 3329*x^10 - 11520*x^9 - 3329*x^8 - 1533*x^7 - 263*x^6 - 218*x^5 - 45*x^4 - 38*x^3 - 7*x^2 - 3*x - 1) / (x^20 - 720898*x^10 + 1). - Colin Barker, Dec 25 2013

a(n) = 720898*a(n-10) - a(n-20) for n > 19. - Vincenzo Librandi, Feb 01 2014

Mathematica

Denominator[Convergents[Sqrt[979], 30]] (* Vincenzo Librandi, Feb 01 2014 *)

Crossrefs

Cf. A042894, A040947.

Sequence in context: A174734 A152560 A162926 * A173561 A258840 A209029

Adjacent sequences: A042892 A042893 A042894 * A042896 A042897 A042898

Keyword

nonn,frac,easy

Author

N. J. A. Sloane

Extensions

More terms from Colin Barker, Dec 25 2013

Status

approved