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A042274
Numerators of continued fraction convergents to sqrt(663).
2
25, 26, 77, 103, 5227, 5330, 15887, 21217, 1076737, 1097954, 3272645, 4370599, 221802595, 226173194, 674148983, 900322177, 45690257833, 46590580010, 138871417853, 185461997863, 9411971311003, 9597433308866
OFFSET
0,1
LINKS
FORMULA
G.f.: (25 +26*x +77*x^2 +103*x^3 +77*x^4 -26*x^5 +25*x^6 -x^7)/(1 -206*x^4 +x^8). - Vincenzo Librandi, Nov 20 2013
a(n) = 206*a(n-4) - a(n-8). - Vincenzo Librandi, Nov 18 2013
MATHEMATICA
Numerator[Convergents[Sqrt[663], 30]] (* Harvey P. Dale, Aug 21 2011 *)
CoefficientList[Series[(25 + 26 x + 77 x^2 + 103 x^3 + 77 x^4 - 26 x^5 + 25 x^6 - x^7)/(1 - 206 x^4 + x^8), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 20 2013 *)
PROG
(Magma) I:=[25, 26, 77, 103, 5227, 5330, 15887, 21217]; [n le 8 select I[n] else 206*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Nov 18 2013
CROSSREFS
Cf. A042275.
Sequence in context: A042252 A042250 A042272 * A042270 A042268 A042266
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved