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A041778
Numerators of continued fraction convergents to sqrt(410).
2
20, 81, 3260, 13121, 528100, 2125521, 85548940, 344321281, 13858400180, 55777922001, 2244975280220, 9035679042881, 363672136995460, 1463724227024721, 58912641217984300, 237114289098961921
OFFSET
0,1
FORMULA
From Colin Barker, Jul 16 2012: (Start)
a(n) = 162*a(n-2) - a(n-4).
G.f.: -(x^3-20*x^2-81*x-20)/(x^4-162*x^2+1). (End)
MATHEMATICA
Numerator[Convergents[Sqrt[410], 40]] (* Vincenzo Librandi, Nov 13 2011 *)
LinearRecurrence[{0, 162, 0, -1}, {20, 81, 3260, 13121}, 30] (* Harvey P. Dale, Jul 19 2015 *)
CROSSREFS
Cf. A041779.
Sequence in context: A244449 A041776 A103532 * A219473 A256869 A156389
KEYWORD
nonn,cofr,frac,easy,less
STATUS
approved