The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A059866 Period length of the continued fraction for sqrt(2^n-1). 6
 2, 4, 2, 8, 2, 12, 2, 20, 2, 12, 2, 164, 2, 40, 2, 40, 2, 1208, 2, 660, 2, 1304, 2, 3056, 2, 2492, 2, 1080, 2, 13004, 2, 10232, 2, 11296, 2, 148736, 2, 56576, 2, 615482, 2, 44448, 2, 64, 2, 2628524, 2, 28219952, 2, 139558, 2, 3067080, 2, 2683626, 2, 90740360, 2, 103050292, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 LINKS Chai Wah Wu, Table of n, a(n) for n = 2..78 EXAMPLE For n=7 and n=8 the quotient periods are: [[11], [3, 1, 2, 2, 7, 11, 7, 2, 2, 1, 3, 22]] and [[15], [1, 30]] with period lengths 12 and 2 respectively. MAPLE with(numtheory): [seq(nops(cfrac(sqrt(2^k-1), 'periodic', 'quotients')[2]), k=2..30)]; MATHEMATICA Table[Length@ Last@ ContinuedFraction[Sqrt[2^n - 1]], {n, 2, 56}] (* Michael De Vlieger, Mar 21 2015 *) CROSSREFS Cf. A003285, A059926, A059927, A064932. Sequence in context: A307669 A171977 A266073 * A278262 A093895 A030057 Adjacent sequences:  A059863 A059864 A059865 * A059867 A059868 A059869 KEYWORD nonn AUTHOR Labos Elemer, Feb 28 2001 EXTENSIONS Corrected and extended by Naohiro Nomoto, Nov 09 2001 a(57)-a(60) from Daniel Suteu, Jan 25 2019 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.

Last modified April 10 17:00 EDT 2021. Contains 342852 sequences. (Running on oeis4.)