A042315 Denominators of continued fraction convergents to sqrt(684).

1, 6, 7, 13, 163, 176, 339, 2210, 115259, 693764, 809023, 1502787, 18842467, 20345254, 39187721, 255471580, 13323709881, 80197730866, 93521440747, 173719171613, 2178151500103, 2351870671716, 4530022171819, 29532003702630, 1540194214708579, 9270697291954104

Offset

0,2

Links

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

Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,115598,0,0,0,0,0,0,0,-1).

Formula

G.f.: -(x^14 -6*x^13 +7*x^12 -13*x^11 +163*x^10 -176*x^9 +339*x^8 -2210*x^7 -339*x^6 -176*x^5 -163*x^4 -13*x^3 -7*x^2 -6*x -1) / ((x^8 -340*x^4 +1)*(x^8 +340*x^4 +1)). - Colin Barker, Dec 28 2013

Mathematica

Denominator[Convergents[Sqrt[684], 30]] (* Vincenzo Librandi, Jan 20 2014 *)

Crossrefs

Cf. A042314, A040657.

Sequence in context: A154741 A041999 A041319 * A288667 A319487 A283772

Adjacent sequences: A042312 A042313 A042314 * A042316 A042317 A042318

Keyword

nonn,frac,easy

Author

N. J. A. Sloane.

Extensions

More terms from Colin Barker, Dec 28 2013

Status

approved