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A042268
Numerators of continued fraction convergents to sqrt(660).
2
25, 26, 77, 334, 745, 1079, 54695, 55774, 166243, 720746, 1607735, 2328481, 118031785, 120360266, 358752317, 1555369534, 3469491385, 5024860919, 254712537335, 259737398254, 774187333843, 3356486733626
OFFSET
0,1
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,2158,0,0,0,0,0,-1).
FORMULA
G.f.: (25 + 26*x + 77*x^2 + 334*x^3 + 745*x^4 + 1079*x^5 + 745*x^6 - 334*x^7 + 77*x^8 - 26*x^9 + 25*x^10 - x^11)/(1 - 2158*x^6 + x^12). - Vincenzo Librandi, Nov 20 2013
a(n) = 2158*a(n-6) - a(n-12). - Vincenzo Librandi, Nov 18 2013
MATHEMATICA
Numerator[Convergents[Sqrt[660], 30]] (* Harvey P. Dale, Oct 11 2011 *)
CoefficientList[Series[(25 + 26 x + 77 x^2 + 334 x^3 + 745 x^4 + 1079 x^5 + 745 x^6 - 334 x^7 + 77 x^8 - 26 x^9 + 25 x^10 - x^11)/(1 - 2158 x^6 + x^12), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 20 2013 *)
PROG
(Magma) I:=[25, 26, 77, 334, 745, 1079, 54695, 55774, 166243, 720746, 1607735, 2328481]; [n le 12 select I[n] else 2158*Self(n-6)-Self(n-12): n in [1..30]]; // Vincenzo Librandi, Nov 18 2013
CROSSREFS
Cf. A042269.
Sequence in context: A042272 A042274 A042270 * A042266 A042278 A042276
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved