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A031614 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 26. 0

%I #12 Aug 18 2021 00:10:32

%S 170,1609,8513,8698,20857,29753,38641,49573,50914,52273,61865,62861,

%T 64877,77725,90529,91733,93554,94778,95393,96629,106901,108209,108866,

%U 110849,111514,112181,113521,124633,128893,143725,146765,149837,152941

%N 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 26.

%t cf26Q[n_]:=Module[{s=Sqrt[n],cf,len},If[IntegerQ[s],cf={1,1},cf = ContinuedFraction[s][[2]]];len=Length[cf];OddQ[len]&&cf[[(len+1)/2]] == 26]; Select[Range[153000],cf26Q] (* _Harvey P. Dale_, Nov 23 2014 *)

%K nonn

%O 1,1

%A _David W. Wilson_

%E Corrected by _Harvey P. Dale_, Nov 23 2014

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Last modified April 28 13:13 EDT 2024. Contains 372086 sequences. (Running on oeis4.)