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A042420
Numerators of continued fraction convergents to sqrt(738).
2
27, 163, 8829, 53137, 2878227, 17322499, 938293173, 5647081537, 305880696171, 1840931258563, 99716168658573, 600137943210001, 32507165101998627, 195643128555201763, 10597236107082893829
OFFSET
0,1
FORMULA
G.f.: (27 + 163*x + 27*x^2 - x^3)/(1 - 326*x^2 + x^4). - Vincenzo Librandi, Nov 24 2013
a(n) = 326*a(n-2) - a(n-4). - Vincenzo Librandi, Nov 24 2013
MATHEMATICA
Numerator[Convergents[Sqrt[738], 30]] (* or *) CoefficientList[Series[(27 + 163 x + 27 x^2 - x^3)/(1 - 326 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 24 2013 *)
PROG
(Magma) I:=[27, 163, 8829, 53137]; [n le 4 select I[n] else 326*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Nov 24 2013
CROSSREFS
Cf. A042421.
Sequence in context: A033262 A224001 A042418 * A372560 A213285 A372444
KEYWORD
nonn,cofr,frac,easy
STATUS
approved