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 A031651 Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 63. 0
 24989, 49333, 80737, 81877, 168269, 169913, 223954, 288658, 289733, 291889, 294053, 365177, 367597, 526154, 530513, 536353, 537818, 540754, 621569, 623146, 627889, 629474, 631061, 634241, 740329, 839897, 843565, 854617, 858317, 955490, 959402, 965285, 971186 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..33. MATHEMATICA opct63Q[n_]:=Module[{s=Sqrt[n], cf, len}, If[IntegerQ[s], cf={}, cf= ContinuedFraction[ s][[2]]]; len=Length[cf]; OddQ[len]&&cf[[(len+1)/2]] == 63]; Select[Range[10^6], opct63Q] (* Harvey P. Dale, Oct 07 2014 *) CROSSREFS Sequence in context: A139776 A214013 A252846 * A263815 A125268 A212726 Adjacent sequences: A031648 A031649 A031650 * A031652 A031653 A031654 KEYWORD nonn AUTHOR David W. Wilson EXTENSIONS Corrected and extended by Harvey P. Dale, Oct 07 2014 STATUS approved

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Last modified November 29 00:31 EST 2023. Contains 367422 sequences. (Running on oeis4.)