login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A031777 Numbers n such that least term in period of continued fraction for sqrt(n) is 99. 1
9803, 39208, 88215, 156824, 245035, 352848, 480263, 627280, 793899, 980120, 1185943, 1411368, 1656395, 1921024, 2205255, 2509088, 2832523, 3175560, 3538199, 3920440, 4322283, 4743728, 5184775, 5645424, 6125675, 6625528, 7144983, 7684040 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

(99*m)^2+2*m for m >= 1 is a proper subsequence (it is a subsequence, see comment in A031749) as the term 97042400 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

lt99Q[n_]:=Module[{s=Sqrt[n], lt}, If[IntegerQ[s], lt=1, lt= Min[ ContinuedFraction[ s][[2]]]]; lt==99]; Select[Range[8000000], lt99Q] (* Harvey P. Dale, Apr 20 2013 *)

PROG

(Python)

from sympy import continued_fraction_periodic

A031777_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) == 99] # Chai Wah Wu, Jun 10 2017

CROSSREFS

Sequence in context: A036353 A174769 A031597 * A237064 A251977 A196897

Adjacent sequences:  A031774 A031775 A031776 * A031778 A031779 A031780

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 19 09:35 EST 2020. Contains 331048 sequences. (Running on oeis4.)