A041154 Numerators of continued fraction convergents to sqrt(87).

9, 28, 513, 1567, 28719, 87724, 1607751, 4910977, 90005337, 274926988, 5038691121, 15391000351, 282076697439, 861621092668, 15791256365463, 48235390189057, 884028279768489, 2700320229494524, 49489792410669921

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..100

Index entries for linear recurrences with constant coefficients, signature (0,56,0,-1).

Formula

G.f.: (9 + 28*x + 9*x^2 - x^3) / (1 - 56*x^2 + x^4). [Bruno Berselli, Oct 29 2013]

a(n) = 56*a(n-2) - a(n-4). [Bruno Berselli, Oct 29 2013]

Mathematica

Numerator[Convergents[Sqrt[87], 30]] (* Vincenzo Librandi, Oct 29 2013 *)

Crossrefs

Cf. A010538, A041155.

Sequence in context: A271185 A306843 A277511 * A024121 A205144 A258483

Adjacent sequences: A041151 A041152 A041153 * A041155 A041156 A041157

Keyword

nonn,cofr,frac,easy

Author

N. J. A. Sloane.

Status

approved