login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A041297 Denominators of continued fraction convergents to sqrt(161). 2
1, 1, 3, 13, 16, 45, 61, 289, 639, 928, 22911, 23839, 70589, 306195, 376784, 1059763, 1436547, 6805951, 15048449, 21854400, 539554049, 561408449, 1662370947, 7210892237, 8873263184, 24957418605, 33830681789, 160280145761, 354390973311, 514671119072 (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 (0,0,0,0,0,0,0,0,0,23550,0,0,0,0,0,0,0,0,0,-1).

FORMULA

G.f.: -(x^18 -x^17 +3*x^16 -13*x^15 +16*x^14 -45*x^13 +61*x^12 -289*x^11 +639*x^10 -928*x^9 -639*x^8 -289*x^7 -61*x^6 -45*x^5 -16*x^4 -13*x^3 -3*x^2 -x -1) / (x^20 -23550*x^10 +1). - Colin Barker, Nov 15 2013

a(n) = 23550*a(n-10) - a(n-20). - Vincenzo Librandi, Dec 15 2013

MATHEMATICA

Denominator[Convergents[Sqrt[161], 30]] (* Vincenzo Librandi, Dec 15 2013 *)

PROG

(MAGMA) I:=[1, 1, 3, 13, 16, 45, 61, 289, 639, 928, 22911, 23839, 70589, 306195, 376784, 1059763, 1436547, 6805951, 15048449, 21854400]; [n le 20 select I[n] else 23550*Self(n-10)-Self(n-20): n in [1..40]]; // Vincenzo Librandi, Dec 15 2013

CROSSREFS

Cf. A041296, A010210.

Sequence in context: A273678 A022124 A042133 * A041815 A042589 A218364

Adjacent sequences:  A041294 A041295 A041296 * A041298 A041299 A041300

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 15 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 15 11:18 EST 2019. Contains 329144 sequences. (Running on oeis4.)