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A041962
Numerators of continued fraction convergents to sqrt(504).
2
22, 45, 202, 449, 19958, 40365, 181418, 403201, 17922262, 36247725, 162913162, 362074049, 16094171318, 32550416685, 146295838058, 325142092801, 14452547921302, 29230237935405, 131373499662922
OFFSET
0,1
FORMULA
G.f.: -(x^7-22*x^6+45*x^5-202*x^4-449*x^3-202*x^2-45*x-22)/(x^8-898*x^4+1). - Vincenzo Librandi, Nov 12 2013
a(n) = 898*a(n-4)-a(n-8). - Vincenzo Librandi, Nov 12 2013
MATHEMATICA
Numerator[Convergents[Sqrt[504], 30]] (* or *) CoefficientList[Series[-(x^7 - 22 x^6 + 45 x^5 - 202 x^4 - 449 x^3 - 202 x^2 - 45 x - 22)/(x^8 - 898 x^4 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 12 2013 *)
PROG
(Magma) I:=[22, 45, 202, 449, 19958, 40365, 181418, 403201]; [n le 8 select I[n] else 898*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Nov 12 2013
CROSSREFS
Cf. A041963.
Sequence in context: A165309 A041960 A041958 * A041964 A041966 A350321
KEYWORD
nonn,cofr,frac,easy,less
AUTHOR
STATUS
approved