login
A041687
Denominators of continued fraction convergents to sqrt(363).
2
1, 19, 723, 13756, 523451, 9959325, 378977801, 7210537544, 274379404473, 5220419222531, 198650309860651, 3779576306574900, 143822549959706851, 2736408025541005069, 104127327520517899473, 1981155630915381095056, 75388041302304999511601
OFFSET
0,2
FORMULA
G.f.: -(x^2-19*x-1) / (x^4-724*x^2+1). - Colin Barker, Nov 21 2013
a(n) = 724*a(n-2) - a(n-4) for n>3. - Vincenzo Librandi, Dec 22 2013
MATHEMATICA
Denominator[Convergents[Sqrt[363], 20]] (* Harvey P. Dale, Dec 10 2013 *)
CoefficientList[Series[(1 + 19 x - x^2)/(x^4 - 724 x^2 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 22 2013 *)
PROG
(Magma) I:=[1, 19, 723, 13756]; [n le 4 select I[n] else 724*Self(n-2)-Self(n-4): n in [1..40]]; // Vincenzo Librandi, Dec 22 2013
CROSSREFS
Sequence in context: A078986 A364299 A180990 * A041684 A157165 A201708
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
Additional term from Colin Barker, Nov 21 2013
STATUS
approved