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A041953
Denominators of continued fraction convergents to sqrt(499).
2
1, 2, 3, 65, 68, 201, 8912, 18025, 26937, 583702, 610639, 1804980, 80029759, 161864498, 241894257, 5241643895, 5483538152, 16208720199, 718667226908, 1453543174015, 2172210400923, 47069961593398, 49242171994321, 145554305582040, 6453631617604081
OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 8980, 0, 0, 0, 0, 0, -1).
FORMULA
G.f.: -(x^10-2*x^9+3*x^8-65*x^7+68*x^6-201*x^5-68*x^4-65*x^3-3*x^2-2*x-1) / (x^12-8980*x^6+1). - Colin Barker, Nov 28 2013
a(n) = 8980*a(n-6) - a(n-12) for n>11. - Vincenzo Librandi, Dec 27 2013
MATHEMATICA
Denominator[Convergents[Sqrt[499], 30]] (* Vincenzo Librandi, Dec 27 2013 *)
PROG
(Magma) I:=[1, 2, 3, 65, 68, 201, 8912, 18025, 26937, 583702, 610639, 1804980]; [n le 12 select I[n] else 8980*Self(n-6)-Self(n-12): n in [1..40]]; // Vincenzo Librandi, Dec 27 2013
CROSSREFS
Sequence in context: A356797 A356785 A015169 * A099080 A132532 A108023
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 28 2013
STATUS
approved