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A042711
Denominators of continued fraction convergents to sqrt(885).
2
1, 1, 3, 4, 235, 239, 713, 952, 55929, 56881, 169691, 226572, 13310867, 13537439, 40385745, 53923184, 3167930417, 3221853601, 9611637619, 12833491220, 753954128379, 766787619599, 2287529367577, 3054316987176, 179437914623785, 182492231610961
OFFSET
0,3
LINKS
FORMULA
G.f.: -(x^2-x-1)*(x^4+4*x^2+1) / (x^8-238*x^4+1). - Colin Barker, Dec 22 2013
a(n) = 238*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Dec 22 2013
MATHEMATICA
Denominator[Convergents[Sqrt[885], 30]] (* Vincenzo Librandi, Dec 22 2013 *)
LinearRecurrence[{0, 0, 0, 238, 0, 0, 0, -1}, {1, 1, 3, 4, 235, 239, 713, 952}, 30] (* Harvey P. Dale, Mar 25 2019 *)
PROG
(Magma) I:=[1, 1, 3, 4, 235, 239, 713, 952]; [n le 8 select I[n] else 238*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 22 2013
CROSSREFS
Sequence in context: A349885 A042485 A111315 * A195566 A348278 A348280
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Dec 22 2013
STATUS
approved