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A042857
Denominators of continued fraction convergents to sqrt(959).
2
1, 1, 30, 31, 1890, 1921, 57599, 59520, 3628799, 3688319, 110590050, 114278369, 6967292190, 7081570559, 212332838401, 219414408960, 13377197376001, 13596611784961, 407678939139870, 421275550924831, 25684211994629730, 26105487545554561, 782743350815711999
OFFSET
0,3
LINKS
FORMULA
G.f.: -(x^2-x-1)*(x^4+31*x^2+1) / (x^8-1920*x^4+1). - Colin Barker, Dec 25 2013
a(n) = 1920*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Dec 25 2013
MATHEMATICA
Denominator[Convergents[Sqrt[959], 30]] (* Vincenzo Librandi, Dec 25 2013 *)
PROG
(Magma) I:=[1, 1, 30, 31, 1890, 1921, 57599, 59520]; [n le 8 select I[n] else 1920*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 25 2013
CROSSREFS
Sequence in context: A042854 A268337 A042856 * A042858 A175514 A043584
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Dec 25 2013
STATUS
approved