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A041249 Denominators of continued fraction convergents to sqrt(136). 2
1, 1, 2, 3, 68, 71, 139, 210, 4759, 4969, 9728, 14697, 333062, 347759, 680821, 1028580, 23309581, 24338161, 47647742, 71985903, 1631337608, 1703323511, 3334661119, 5037984630, 114170322979, 119208307609, 233378630588, 352586938197, 7990291270922 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (0,0,0,70,0,0,0,-1).

FORMULA

G.f.: -(x^2-x-1)*(x^4+3*x^2+1) / (x^8-70*x^4+1). - Colin Barker, Nov 14 2013

a(n) = 70*a(n-4) - a(n-8). - Vincenzo Librandi, Dec 13 2013

MATHEMATICA

Denominator[Convergents[Sqrt[136], 30]]  (* Vincenzo Librandi, Dec 13 2013 *)

PROG

(MAGMA) I:=[1, 1, 2, 3, 68, 71, 139, 210]; [n le 8 select I[n] else 70*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 13 2013

CROSSREFS

Cf. A041248, A010195.

Sequence in context: A099080 A132532 A108023 * A184949 A132598 A257173

Adjacent sequences:  A041246 A041247 A041248 * A041250 A041251 A041252

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 14 2013

STATUS

approved

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Last modified November 28 00:12 EST 2021. Contains 349395 sequences. (Running on oeis4.)