A031769 Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 91.

8283, 33128, 74535, 132504, 207035, 298128, 405783, 530000, 670779, 828120, 1002023, 1192488, 1399515, 1623104, 1863255, 2119968, 2393243, 2683080, 2989479, 3312440, 3651963, 4008048, 4380695, 4769904, 5175675, 5598008, 6036903, 6492360

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

(91*m)^2+2*m for m >= 1 is a proper subsequence. It is a subsequence (see comment in A031749) and the term 69339112 is not of this form. - Chai Wah Wu, Jun 19 2016

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Programs

Mathematica

cf91Q[n_]:=Module[{s=Sqrt[n]},If[IntegerQ[s],1,Min[ContinuedFraction[s][[2]]]]==91]; Select[Range[65*10^5],cf91Q] (* Harvey P. Dale, Oct 08 2016 *)