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A041487
Denominators of continued fraction convergents to sqrt(260).
2
1, 8, 257, 2064, 66305, 532504, 17106433, 137383968, 4413393409, 35444531240, 1138638393089, 9144551675952, 293764292023553, 2359258887864376, 75790048703683585, 608679648517333056, 19553538801258341377, 157036990058584064072, 5044737220675948391681
OFFSET
0,2
FORMULA
G.f.: -(x^2-8*x-1) / ((x^2-16*x-1)*(x^2+16*x-1)). - Colin Barker, Nov 18 2013
a(n) = 258*a(n-2) - a(n-4) for n>3. - Vincenzo Librandi, Dec 18 2013
MATHEMATICA
Denominator[Convergents[Sqrt[260], 30]] (* Vincenzo Librandi, Dec 18 2013 *)
PROG
(Magma) I:=[1, 8, 257, 2064]; [n le 4 select I[n] else 258*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 18 2013
CROSSREFS
Sequence in context: A140339 A103488 A341479 * A034988 A230271 A221778
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 18 2013
STATUS
approved