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 A061682 Length of period of continued fraction expansion of square root of (2^(2n+1)+1). 1
 4, 10, 16, 44, 74, 46, 204, 714, 702, 908, 404, 7754, 1136, 9886, 8154, 23578, 65096, 404762, 23992, 3514774, 110124, 4802160, 6490450, 180832, 115972, 770304, 62665998, 133093360, 1019300318, 60079334, 113987888, 5702124038, 4463754028, 713372392, 38574516706, 9096543466, 7030527700, 582442851838, 16708770664, 32628786870 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 COMMENTS Old definition was: "Quotient cycle length in continued fraction expansion of sqrt(2^(2n+1)+1)." LINKS FORMULA a(n) = A003285(A087289(n)). - Michel Marcus, Sep 26 2019 MATHEMATICA a[n_] := ContinuedFraction[Sqrt[2^(2n+1)+1]] // Last // Length; Table[a[n], {n, 2, 28}] (* Jean-François Alcover, Dec 11 2016 *) CROSSREFS Cf. A003285, A059866, A059926, A087289. Sequence in context: A025621 A056486 A233452 * A246882 A038240 A211160 Adjacent sequences:  A061679 A061680 A061681 * A061683 A061684 A061685 KEYWORD nonn,nice,more AUTHOR Labos Elemer, Mar 01 2001 EXTENSIONS One more term from David W. Wilson, Jun 18 2001 Corrected and extended by Naohiro Nomoto, Nov 09 2001 a(29)-a(31) from Daniel Suteu, Jan 25 2019 a(32) from Chai Wah Wu, Sep 23 2019 a(33)-a(38) from Chai Wah Wu, Sep 25 2019 Simpler definition from Bernard Schott, Sep 26 2019 a(39)-a(41) from Chai Wah Wu, Sep 29 2019 STATUS approved

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Last modified August 2 02:22 EDT 2021. Contains 346408 sequences. (Running on oeis4.)