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A042261
Denominators of continued fraction convergents to sqrt(656).
2
1, 1, 2, 3, 5, 13, 18, 31, 49, 80, 4049, 4129, 8178, 12307, 20485, 53277, 73762, 127039, 200801, 327840, 16592801, 16920641, 33513442, 50434083, 83947525, 218329133, 302276658, 520605791, 822882449, 1343488240, 67997294449, 69340782689, 137338077138
OFFSET
0,3
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,0,4098,0,0,0,0,0,0,0,0,0,-1).
FORMULA
G.f.: -(x^4-3*x^3+4*x^2-2*x+1)*(x^4+2*x^3+4*x^2+3*x+1)*(x^10-16*x^5-1) / ((x^10-64*x^5-1)*(x^10+64*x^5-1)). - Colin Barker, Dec 06 2013
MAPLE
convert(sqrt(656), confrac, 30, cvgts): denom(cvgts); # Wesley Ivan Hurt, Dec 07 2013
MATHEMATICA
Denominator[Convergents[Sqrt[656], 30]] (* Harvey P. Dale, Jun 04 2013 *)
PROG
(Magma) I:=[1, 1, 2, 3, 5, 13, 18, 31, 49, 80, 4049, 4129, 8178, 12307, 20485, 53277, 73762, 127039, 200801, 327840]; [n le 20 select I[n] else 4098*Self(n-10)-Self(n-20): n in [1..40]]; // Vincenzo Librandi, Jan 19 2014
CROSSREFS
Sequence in context: A349785 A087356 A281598 * A112596 A179238 A041385
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Dec 06 2013
STATUS
approved