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A041809 Denominators of continued fraction convergents to sqrt(425). 2
1, 1, 2, 3, 5, 8, 13, 528, 541, 1069, 1610, 2679, 4289, 6968, 283009, 289977, 572986, 862963, 1435949, 2298912, 3734861, 151693352, 155428213, 307121565, 462549778, 769671343, 1232221121, 2001892464, 81307919681, 83309812145, 164617731826, 247927543971 (list; graph; refs; listen; history; text; internal format)
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, 536, 0, 0, 0, 0, 0, 0, 1).

FORMULA

G.f.: -(x^12-x^11+2*x^10-3*x^9+5*x^8-8*x^7+13*x^6+8*x^5+5*x^4+3*x^3+2*x^2+x+1) / (x^14+536*x^7-1). - Colin Barker, Nov 25 2013

a(n) = 536*a(n-7) + a(n-14) for n>13. - Vincenzo Librandi, Dec 24 2013

MATHEMATICA

Denominator[Convergents[Sqrt[425], 30]] (* Vincenzo Librandi, Dec 24 2013 *)

LinearRecurrence[{0, 0, 0, 0, 0, 0, 536, 0, 0, 0, 0, 0, 0, 1}, {1, 1, 2, 3, 5, 8, 13, 528, 541, 1069, 1610, 2679, 4289, 6968}, 40] (* Harvey P. Dale, Dec 02 2014 *)

PROG

(MAGMA) I:=[1, 1, 2, 3, 5, 8, 13, 528, 541, 1069, 1610, 2679, 4289, 6968]; [n le 14 select I[n] else 536*Self(n-7)+Self(n-14): n in [1..50]]; // Vincenzo Librandi, Dec 24 2013

CROSSREFS

Cf. A041808, A040404.

Sequence in context: A294939 A096095 A041101 * A117566 A123000 A132599

Adjacent sequences:  A041806 A041807 A041808 * A041810 A041811 A041812

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 25 2013

STATUS

approved

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Last modified March 18 23:08 EDT 2019. Contains 321305 sequences. (Running on oeis4.)