login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A042925 Denominators of continued fraction convergents to sqrt(994). 2
1, 1, 2, 17, 19, 36, 2251, 2287, 4538, 38591, 43129, 81720, 5109769, 5191489, 10301258, 87601553, 97902811, 185504364, 11599173379, 11784677743, 23383851122, 198855486719, 222239337841, 421094824560, 26330118460561, 26751213285121, 53081331745682 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 2270, 0, 0, 0, 0, 0, -1).
FORMULA
G.f.: -(x^4 - x^3 + 2*x^2 + x + 1)*(x^6 - 18*x^3 - 1) / (x^12 - 2270*x^6 + 1). - Colin Barker, Dec 25 2013
a(n) = 2270*a(n-6) - a(n-12) for n>11. - Vincenzo Librandi, Feb 01 2014
MATHEMATICA
Denominator[Convergents[Sqrt[994], 30]] (* Vincenzo Librandi, Feb 01 2014 *)
LinearRecurrence[{0, 0, 0, 0, 0, 2270, 0, 0, 0, 0, 0, -1}, {1, 1, 2, 17, 19, 36, 2251, 2287, 4538, 38591, 43129, 81720}, 30] (* Harvey P. Dale, Oct 27 2018 *)
PROG
(Magma) I:=[1, 1, 2, 17, 19, 36, 2251, 2287, 4538, 38591, 43129, 81720]; [n le 12 select I[n] else 2270*Self(n-6)-Self(n-12): n in [1..30]]; // Vincenzo Librandi, Feb 01 2014
CROSSREFS
Sequence in context: A018569 A022118 A041339 * A019413 A040138 A240475
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Dec 25 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 12 10:04 EDT 2024. Contains 371627 sequences. (Running on oeis4.)