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A042675
Denominators of continued fraction convergents to sqrt(867).
2
1, 2, 9, 263, 1061, 2385, 139391, 281167, 1264059, 36938878, 149019571, 334978020, 19577744731, 39490467482, 177539614659, 5188139292593, 20930096785031, 47048332862655, 2749733402819021, 5546515138500697, 24935793956821809, 728684539886333158
OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 140452, 0, 0, 0, 0, 0, -1).
FORMULA
G.f.: -(x^10 -2*x^9 +9*x^8 -263*x^7 +1061*x^6 -2385*x^5 -1061*x^4 -263*x^3 -9*x^2 -2*x -1) / ((x^4 -52*x^2 +1)*(x^8 +52*x^6 +2703*x^4 +52*x^2 +1)). - Colin Barker, Dec 20 2013
a(n) = 140452*a(n-6) - a(n-12) for n>11. - Vincenzo Librandi, Dec 20 2013
MATHEMATICA
Denominator[Convergents[Sqrt[867], 30]] (* Vincenzo Librandi, Dec 20 2013 *)
LinearRecurrence[{0, 0, 0, 0, 0, 140452, 0, 0, 0, 0, 0, -1}, {1, 2, 9, 263, 1061, 2385, 139391, 281167, 1264059, 36938878, 149019571, 334978020}, 30] (* Harvey P. Dale, May 11 2024 *)
PROG
(Magma) I:=[1, 2, 9, 263, 1061, 2385, 139391, 281167, 1264059, 36938878, 149019571, 334978020]; [n le 12 select I[n] else 140452*Self(n-6)-Self(n-12): n in [1..40]]; // Vincenzo Librandi, Dec 20 2013
CROSSREFS
Sequence in context: A165797 A011823 A122894 * A308647 A015177 A005271
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Dec 20 2013
STATUS
approved