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A041853
Denominators of continued fraction convergents to sqrt(448).
2
1, 6, 253, 1524, 64261, 387090, 16322041, 98319336, 4145734153, 24972724254, 1053000152821, 6342973641180, 267457893082381, 1611090332135466, 67933251842771953, 409210601388767184, 17254778510170993681, 103937881662414729270, 4382645808331589623021
OFFSET
0,2
FORMULA
G.f.: -(x^2 -6*x -1) / ((x^2 -16*x +1)*(x^2 +16*x +1)). - Colin Barker, Nov 26 2013
a(n) = 254*a(n-2) - a(n-4) for n>3. - Vincenzo Librandi, Dec 25 2013
MATHEMATICA
Denominator/@Convergents[Sqrt[448], 20] (* Harvey P. Dale, Apr 06 2011 *)
PROG
(Magma) I:=[1, 6, 253, 1524]; [n le 4 select I[n] else 254*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 25 2013
CROSSREFS
Sequence in context: A324478 A230881 A332563 * A168476 A320979 A279869
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 26 2013
STATUS
approved