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A041187
Denominators of continued fraction convergents to sqrt(104).
2
1, 5, 101, 510, 10301, 52015, 1050601, 5305020, 107151001, 541060025, 10928351501, 55182817530, 1114584702101, 5628106328035, 113676711262801, 574011662642040, 11593909964103601, 58543561483160045, 1182465139627304501, 5970869259619682550
OFFSET
0,2
FORMULA
G.f.: (1 + 5*x - x^2)/(1 - 102*x^2 + x^4). - Vincenzo Librandi, Dec 12 2013
a(n) = 102*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 12 2013
MATHEMATICA
Denominator[Convergents[Sqrt[104], 30]] (* or *) CoefficientList[Series[(1 + 5 x - x^2)/(1 - 102 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 12 2013 *)
LinearRecurrence[{0, 102, 0, -1}, {1, 5, 101, 510}, 30] (* Harvey P. Dale, Mar 12 2015 *)
PROG
(Magma) I:=[1, 5, 101, 510]; [n le 4 select I[n] else 102*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 12 2013
CROSSREFS
Cf. A041186.
Sequence in context: A087456 A081220 A210362 * A266235 A266452 A354332
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Vincenzo Librandi, Dec 12 2013
STATUS
approved