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A041717 Denominators of continued fraction convergents to sqrt(378). 2
1, 2, 7, 9, 43, 52, 199, 450, 17299, 35048, 122443, 157491, 752407, 909898, 3482101, 7874100, 302697901, 613269902, 2142507607, 2755777509, 13165617643, 15921395152, 60929803099, 137781001350, 5296607854399, 10730996710148, 37489597984843, 48220594694991 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,17498,0,0,0,0,0,0,0,-1).

FORMULA

G.f.: -(x^14 -2*x^13 +7*x^12 -9*x^11 +43*x^10 -52*x^9 +199*x^8 -450*x^7 -199*x^6 -52*x^5 -43*x^4 -9*x^3 -7*x^2 -2*x -1) / (x^16 -17498*x^8 +1). - Colin Barker, Nov 22 2013

a(n) = 17498*a(n-8) - a(n-16) for n>15. - Vincenzo Librandi, Dec 23 2013

MATHEMATICA

Denominator[Convergents[Sqrt[378], 30]] (* Vincenzo Librandi, Dec 23 2013 *)

PROG

(MAGMA) I:=[1, 2, 7, 9, 43, 52, 199, 450, 17299, 35048, 122443, 157491, 752407, 909898, 3482101, 7874100]; [n le 16 select I[n] else 17498*Self(n-8)-Self(n-16): n in [1..40]]; // Vincenzo Librandi, Dec 23 2013

CROSSREFS

Cf. A041716, A040358.

Sequence in context: A126871 A125770 A042063 * A002353 A041073 A079942

Adjacent sequences:  A041714 A041715 A041716 * A041718 A041719 A041720

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 22 2013

STATUS

approved

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Last modified September 22 08:23 EDT 2021. Contains 347605 sequences. (Running on oeis4.)