A031530 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 32.

1026, 1046, 1054, 1058, 1062, 1074, 1094, 1126, 1142, 1154, 2307, 2361, 2382, 2388, 2409, 2433, 2451, 2469, 2481, 2487, 2517, 2526, 2532, 2553, 2559, 2577, 2589, 2598, 4100, 4124, 4132, 4140, 4148, 4156, 4196, 4204, 4236, 4244, 4252, 4268, 4276, 4292

Offset

1,1

Links

Table of n, a(n) for n=1..42.

Mathematica

cf32Q[n_]:=Module[{s=Sqrt[n], cf, len}, cf=If[IntegerQ[s], {1}, ContinuedFraction[ s][[2]]]; len=Length[cf]; EvenQ[len]&&cf[[len/2]]==32]; Select[Range[5000], cf32Q] (* Harvey P. Dale, Sep 11 2022 *)

Crossrefs

Sequence in context: A103716 A291508 A371982 * A004607 A361811 A221008

Adjacent sequences: A031527 A031528 A031529 * A031531 A031532 A031533

Keyword

nonn

Author

David W. Wilson

Extensions

Definition edited by Harvey P. Dale, Sep 11 2022

Status

approved