A042499 Denominators of continued fraction convergents to sqrt(777).

1, 1, 7, 8, 439, 447, 3121, 3568, 195793, 199361, 1391959, 1591320, 87323239, 88914559, 620810593, 709725152, 38945968801, 39655693953, 276880132519, 316535826472, 17369814762007, 17686350588479

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, 446, 0, 0, 0, -1).

Formula

a(n) = 446*a(n-4)-a(n-8). G.f.: -(x^2-x-1)*(x^4+8*x^2+1)/(x^8-446*x^4+1). [Colin Barker, Jul 16 2012]

Mathematica

Denominator[Convergents[Sqrt[777], 30]] (* Vincenzo Librandi, Oct 25 2013 *)

Crossrefs

Cf. A042498.

Sequence in context: A041473 A041751 A042093 * A156206 A226487 A360990

Adjacent sequences: A042496 A042497 A042498 * A042500 A042501 A042502

Keyword

nonn,cofr,frac,easy

Author

N. J. A. Sloane.

Status

approved