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A031775 Least term in period of continued fraction for sqrt(n) is 97. 1
9411, 37640, 84687, 150552, 235235, 338736, 461055, 602192, 762147, 940920, 1138511, 1354920, 1590147, 1844192, 2117055, 2408736, 2719235, 3048552, 3396687, 3763640, 4149411, 4554000, 4977407, 5419632, 5880675, 6360536, 6859215, 7376712 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

(97*m)^2+2*m for m >= 1 are terms of the sequence (see comment in A031749). The term 89453959 is not of this form. - Chai Wah Wu, Jun 19 2016

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000

MATHEMATICA

cf97Q[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 1, Min[ContinuedFraction[s][[2]]]]==97]; Select[Range[738*10^4], cf97Q] (* Harvey P. Dale, Nov 20 2018 *)

PROG

(Python)

from sympy import continued_fraction_periodic

A031775_list = [n for n, d in ((n, continued_fraction_periodic(0, 1, n)[-1]) for n in range(1, 10**5)) if isinstance(d, list) and min(d) == 97] # Chai Wah Wu, Jun 10 2017

CROSSREFS

Sequence in context: A206251 A264340 A031595 * A143367 A234432 A235677

Adjacent sequences:  A031772 A031773 A031774 * A031776 A031777 A031778

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified May 7 23:48 EDT 2021. Contains 343652 sequences. (Running on oeis4.)