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A041425
Denominators of continued fraction convergents to sqrt(228).
2
1, 10, 301, 3020, 90901, 912030, 27451801, 275430040, 8290353001, 83178960050, 2503659154501, 25119770505060, 756096774306301, 7586087513568070, 228338722181348401, 2290973309327052080, 68957538001992910801, 691866353329256160090, 20824948137879677713501
OFFSET
0,2
FORMULA
G.f.: -(x^2-10*x-1) / (x^4-302*x^2+1). - Colin Barker, Nov 17 2013
a(n) = 302*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 17 2013
MATHEMATICA
Denominator[Convergents[Sqrt[228], 30]] (* Vincenzo Librandi, Dec 17 2013 *)
PROG
(Magma) I:=[1, 10, 301, 3020]; [n le 4 select I[n] else 302*Self(n-2)-Self(n-4): n in [1..100]]; // Vincenzo Librandi, Dec 17 2013
CROSSREFS
Sequence in context: A293963 A152165 A228188 * A217505 A222972 A119297
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 17 2013
STATUS
approved