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A041673 Denominators of continued fraction convergents to sqrt(355). 2
1, 1, 6, 19, 63, 82, 555, 637, 2466, 8035, 42641, 50676, 1866977, 1917653, 11455242, 36283379, 120305379, 156588758, 1059837927, 1216426685, 4709117982, 15343780631, 81428021137, 96771801768, 3565212884785, 3661984686553, 21875136317550, 69287393639203 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

FORMULA

G.f.: -(x^22 -x^21 +6*x^20 -19*x^19 +63*x^18 -82*x^17 +555*x^16 -637*x^15 +2466*x^14 -8035*x^13 +42641*x^12 -50676*x^11 -42641*x^10 -8035*x^9 -2466*x^8 -637*x^7 -555*x^6 -82*x^5 -63*x^4 -19*x^3 -6*x^2 -x -1)/(x^24 -1909618*x^12 +1). - Vincenzo Librandi, Dec 22 2013

a(n) = 1909618*a(n-12) - a(n-24) for n>23. - Vincenzo Librandi, Dec 22 2013

MATHEMATICA

Denominator/@Convergents[Sqrt[355], 40] (* Harvey P. Dale, May 11 2011 *)

CoefficientList[Series[-(x^22 - x^21 + 6 x^20 - 19 x^19 + 63 x^18 - 82 x^17 + 555 x^16 - 637 x^15 + 2466 x^14 - 8035 x^13 + 42641 x^12 - 50676 x^11 - 42641 x^10 - 8035 x^9 - 2466 x^8 - 637 x^7 - 555 x^6 - 82 x^5 - 63 x^4 - 19 x^3 - 6 x^2 - x - 1)/(x^24 - 1909618 x^12 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 22 2013 *)

CROSSREFS

Cf. A041672.

Sequence in context: A080926 A184189 A152098 * A137195 A055916 A266472

Adjacent sequences:  A041670 A041671 A041672 * A041674 A041675 A041676

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Harvey P. Dale, May 11 2011.

STATUS

approved

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Last modified September 20 21:12 EDT 2019. Contains 327247 sequences. (Running on oeis4.)