

A031597


Numbers n such that continued fraction for sqrt(n) has even period and central term 99.


1



9803, 9811, 9839, 9843, 9851, 9859, 9871, 9883, 9887, 9899, 9907, 9923, 9931, 9959, 9963, 9967, 9987, 9991, 10007, 10019, 10031, 10039, 10067, 10079, 10083, 10091, 10099, 10103, 10107, 10111, 10131, 10139, 10147, 10151, 10159, 10163, 10199, 39208
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OFFSET

1,1


LINKS

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


PROG

(Python)
from __future__ import division
from sympy import continued_fraction_periodic
A031597_list = [n for n, s in ((i, continued_fraction_periodic(0, 1, i)[1]) for i in range(1, 10**5)) if isinstance(s, list) and len(s) % 2 == 0 and s[len(s)//21] == 99] # Chai Wah Wu, Jun 10 2017


CROSSREFS

Sequence in context: A113937 A036353 A174769 * A031777 A237064 A251977
Adjacent sequences: A031594 A031595 A031596 * A031598 A031599 A031600


KEYWORD

nonn


AUTHOR

David W. Wilson


STATUS

approved



