A041917 Denominators of continued fraction convergents to sqrt(480).

1, 1, 10, 11, 472, 483, 4819, 5302, 227503, 232805, 2322748, 2555553, 109655974, 112211527, 1119559717, 1231771244, 52853951965, 54085723209, 539625460846, 593711184055, 25475495191156, 26069206375211, 260098352568055, 286167558943266, 12279135828185227

Offset

0,3

Links

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

Index entries for linear recurrences with constant coefficients, signature (0,0,0,482,0,0,0,-1).

Formula

a(n) = 482*a(n-4)-a(n-8). G.f.: -(x^2-x-1)*(x^4+11*x^2+1)/((x^4-22*x^2+1)*(x^4+22*x^2+1)). [Colin Barker, Jul 16 2012]

Mathematica

Table[Denominator[FromContinuedFraction[ContinuedFraction[Sqrt[480], n]]], {n, 1, 50}] (* Vladimir Joseph Stephan Orlovsky, Jun 23 2011 *)
Denominator[Convergents[Sqrt[480], 30]] (* Vincenzo Librandi, Oct 25 2013 *)

Crossrefs

Cf. A041916.

Sequence in context: A041217 A041218 A300458 * A318089 A109280 A181756

Adjacent sequences: A041914 A041915 A041916 * A041918 A041919 A041920

Keyword

nonn,cofr,frac,easy

Author

N. J. A. Sloane.

Status

approved