OFFSET
2,1
LINKS
Chai Wah Wu, Table of n, a(n) for n = 2..78
EXAMPLE
For n=7 and n=8 the continued fractions are [[11], [3, 1, 2, 2, 7, 11, 7, 2, 2, 1, 3, 22]] and [[15], [1, 30]] with periods 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
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