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A041045 Denominators of continued fraction convergents to sqrt(28). 2
1, 3, 7, 24, 247, 765, 1777, 6096, 62737, 194307, 451351, 1548360, 15934951, 49353213, 114641377, 393277344, 4047414817, 12535521795, 29118458407, 99890897016, 1028027428567, 3183973182717, 7395973794001 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
a(n) = 254*a(n-4)-a(n-8). G.f.: -(x^2-3*x-1)*(x^4+8*x^2+1)/((x^4-16*x^2+1)*(x^4+16*x^2+1)). [Colin Barker, Jul 16 2012]
MATHEMATICA
Table[Denominator[FromContinuedFraction[ContinuedFraction[Sqrt[28], n]]], {n, 1, 50}] (* Vladimir Joseph Stephan Orlovsky, Mar 18 2011 *)
CoefficientList[Series[- (x^2 - 3 x - 1) (x^4 + 8 x^2 + 1)/((x^4 - 16 x^2 + 1) (x^4 + 16 x^2 + 1)), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 23 2013 *)
CROSSREFS
Sequence in context: A005642 A019055 A300515 * A041563 A042657 A031875
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved

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Last modified April 19 16:52 EDT 2024. Contains 371794 sequences. (Running on oeis4.)