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A042710
Numerators of continued fraction convergents to sqrt(885).
2
29, 30, 89, 119, 6991, 7110, 21211, 28321, 1663829, 1692150, 5048129, 6740279, 395984311, 402724590, 1201433491, 1604158081, 94242602189, 95846760270, 285936122729, 381782882999, 22429343336671, 22811126219670
OFFSET
0,1
LINKS
FORMULA
G.f.: (29 +30*x +89*x^2 +119*x^3 +89*x^4 -30*x^5 +29*x^6 -x^7)/(1 -238*x^4 +x^8). - Vincenzo Librandi, Dec 02 2013
a(n) = 238*a(n-4) - a(n-8). - Vincenzo Librandi, Dec 02 2013
MATHEMATICA
Numerator[Convergents[Sqrt[885], 30]] (* or *) CoefficientList[Series[(29 + 30 x + 89 x^2 + 119 x^3 + 89 x^4 - 30 x^5 + 29 x^6 - x^7)/(1 - 238 x^4 + x^8), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 02 2013 *)
LinearRecurrence[{0, 0, 0, 238, 0, 0, 0, -1}, {29, 30, 89, 119, 6991, 7110, 21211, 28321}, 30] (* Harvey P. Dale, May 15 2018 *)
PROG
(Magma) I:=[29, 30, 89, 119, 6991, 7110, 21211, 28321]; [n le 8 select I[n] else 238*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Dec 02 2013
CROSSREFS
Cf. A042711.
Sequence in context: A042682 A042706 A042708 * A042704 A042702 A042714
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved