A042169 Denominators of continued fraction convergents to sqrt(609).

1, 1, 3, 28, 31, 59, 385, 444, 829, 7905, 16639, 24544, 1194751, 1219295, 3633341, 33919364, 37552705, 71472069, 466385119, 537857188, 1004242307, 9576037951, 20156318209, 29732356160, 1447309413889, 1477041770049, 4401392953987, 41089578355932

Offset

0,3

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, 0, 0, 1211390, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).

Formula

G.f.: -(x^22 - x^21 + 3*x^20 - 28*x^19 + 31*x^18 - 59*x^17 + 385*x^16 - 444*x^15 + 829*x^14 - 7905*x^13 + 16639*x^12 - 24544*x^11 - 16639*x^10 - 7905*x^9 - 829*x^8 - 444*x^7 - 385*x^6 - 59*x^5 - 31*x^4 - 28*x^3 - 3*x^2 - x - 1) / (x^24 - 1211390*x^12 + 1). - Colin Barker, Dec 03 2013

Mathematica

Denominator[Convergents[Sqrt[609], 30]] (* Vincenzo Librandi, Jan 16 2014 *)

Crossrefs

Cf. A042168, A040584.

Sequence in context: A064234 A224579 A037102 * A041785 A157848 A225674

Adjacent sequences: A042166 A042167 A042168 * A042170 A042171 A042172

Keyword

nonn,frac,easy

Author

N. J. A. Sloane

Extensions

More terms from Colin Barker, Dec 03 2013

Status

approved