A031527 - OEIS

%I #14 Jul 06 2024 15:58:45

%S 843,859,863,867,883,887,907,911,919,947,959,3368,3392,3424,3456,3488,

%T 3520,3552,3584,3616,3648,3656,3680,3688,3712,3776,3840,7575,7635,

%U 7647,7719,7779,7851,7863,8079,8223,8355,8367,8427,8439,8511,8571,8583,8643

%N Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 29.

%t cf29Q[n_]:=Module[{s=Sqrt[n],cf,len},cf=If[IntegerQ[s],{1},ContinuedFraction[ s][[2]]];len=Length[cf];EvenQ[len]&& cf[[len/2 ]] == 29]; Select[Range[9000],cf29Q] (* _Harvey P. Dale_, Jul 18 2021 *)

%K nonn

%O 1,1

%A _David W. Wilson_