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A041293
Denominators of continued fraction convergents to sqrt(159).
2
1, 1, 2, 3, 5, 18, 23, 41, 64, 105, 2584, 2689, 5273, 7962, 13235, 47667, 60902, 108569, 169471, 278040, 6842431, 7120471, 13962902, 21083373, 35046275, 126222198, 161268473, 287490671, 448759144, 736249815, 18118754704, 18855004519, 36973759223, 55828763742
OFFSET
0,3
LINKS
Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 2648, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).
FORMULA
G.f.: -(x^4-3*x^3+4*x^2-2*x+1)*(x^4+2*x^3+4*x^2+3*x+1)*(x^10-21*x^5-1) / (x^20-2648*x^10+1). - Colin Barker, Nov 14 2013
a(n) = 2648*a(n-10) - a(n-20). - Vincenzo Librandi, Dec 15 2013
MATHEMATICA
Denominator[Convergents[Sqrt[159], 30]] (* Vincenzo Librandi, Dec 15 2013 *)
PROG
(Magma) I:=[1, 1, 2, 3, 5, 18, 23, 41, 64, 105, 2584, 2689, 5273, 7962, 13235, 47667, 60902, 108569, 169471, 278040]; [n le 20 select I[n] else 2648*Self(n-10)-Self(n-20): n in [1..40]]; // Vincenzo Librandi, Dec 15 2013
CROSSREFS
Sequence in context: A121510 A132346 A284530 * A041713 A042555 A041891
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 14 2013
STATUS
approved