OFFSET
1,1
COMMENTS
All the terms of A005563 are here, as well as some additional terms (with even period > 2 and the digit 1 in central position) (e.g., sqrt(175) = [13,'4, 2, 1, 2, 4, 26']).
REFERENCES
Kenneth H. Rosen, Elementary Number Theory and Its Applications, Addison-Wesley, 1984, page 426 (but beware of errors!).
LINKS
T. D. Noe, Table of n, a(n) for n = 1..1000
R. Macmillan, Continued fractions, Math. Gaz. 84, 2000. See p. 34.
MATHEMATICA
Select[ Range@ 1900, !IntegerQ[ Sqrt@ #] && Count[ ContinuedFraction[ Sqrt@ #][[2]], 1] == 1 &] (* Robert G. Wilson v, Jul 03 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Additional comments from Francisco Salinas (franciscodesalinas(AT)hotmail.com), Dec 30 2001
Incorrect formulas and programs removed by R. J. Mathar, Jan 06 2011
STATUS
approved