A042715 Denominators of continued fraction convergents to sqrt(887).

1, 1, 4, 5, 9, 23, 676, 1375, 2051, 3426, 12329, 15755, 926119, 941874, 3751741, 4693615, 8445356, 21584327, 634390839, 1290366005, 1924756844, 3215122849, 11570125391, 14785248240, 869114523311, 883899771551, 3520813837964, 4404713609515, 7925527447479

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, 938448, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).

Formula

G.f.: -(x^22 -x^21 +4*x^20 -5*x^19 +9*x^18 -23*x^17 +676*x^16 -1375*x^15 +2051*x^14 -3426*x^13 +12329*x^12 -15755*x^11 -12329*x^10 -3426*x^9 -2051*x^8 -1375*x^7 -676*x^6 -23*x^5 -9*x^4 -5*x^3 -4*x^2 -x -1) / (x^24 -938448*x^12 +1). - Colin Barker, Dec 22 2013

a(n) = 938448*a(n-12) - a(n-24). - Wesley Ivan Hurt, Apr 11 2022

Mathematica

Denominator[Convergents[Sqrt[887], 30]] (* Vincenzo Librandi, Jan 27 2014 *)

Crossrefs

Cf. A042714, A040857.

Sequence in context: A153068 A075116 A041079 * A163868 A019148 A360699

Adjacent sequences: A042712 A042713 A042714 * A042716 A042717 A042718

Keyword

nonn,frac,easy

Author

N. J. A. Sloane.

Extensions

More terms from Colin Barker, Dec 22 2013

Status

approved