%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
