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A041485
Denominators of continued fraction convergents to sqrt(259).
2
1, 10, 11, 32, 107, 460, 1487, 3434, 4921, 52644, 1689529, 16947934, 18637463, 54222860, 181306043, 779447032, 2519647139, 5818741310, 8338388449, 89202625800, 2862822414049, 28717426766290, 31580249180339, 91877925126968, 307214024561243, 1320734023371940
OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 1694450, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).
FORMULA
G.f.: -(x^18 -10*x^17 +11*x^16 -32*x^15 +107*x^14 -460*x^13 +1487*x^12 -3434*x^11 +4921*x^10 -52644*x^9 -4921*x^8 -3434*x^7 -1487*x^6 -460*x^5 -107*x^4 -32*x^3 -11*x^2 -10*x -1) / (x^20 -1694450*x^10 +1). - Colin Barker, Nov 18 2013
a(n) = 1694450*a(n-10) - a(n-20) for n>19. - Vincenzo Librandi, Dec 18 2013
MATHEMATICA
Denominator[Convergents[Sqrt[259], 30]] (* Vincenzo Librandi, Dec 18 2013 *)
LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 0, 0, 1694450, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1}, {1, 10, 11, 32, 107, 460, 1487, 3434, 4921, 52644, 1689529, 16947934, 18637463, 54222860, 181306043, 779447032, 2519647139, 5818741310, 8338388449, 89202625800}, 40] (* Harvey P. Dale, Aug 03 2021 *)
PROG
(Magma) I:=[1, 10, 11, 32, 107, 460, 1487, 3434, 4921, 52644, 1689529, 16947934, 18637463, 54222860, 181306043, 779447032, 2519647139, 5818741310, 8338388449, 89202625800]; [n le 20 select I[n] else 1694450*Self(n-10)-Self(n-20): n in [1..40]]; // Vincenzo Librandi, Dec 18 2013
CROSSREFS
Sequence in context: A108580 A356279 A041208 * A041206 A376219 A339078
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 18 2013
STATUS
approved