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A041051 Denominators of continued fraction convergents to sqrt(31). 2
1, 1, 2, 7, 37, 118, 155, 273, 2885, 3158, 6043, 21287, 112478, 358721, 471199, 829920, 8770399, 9600319, 18370718, 64712473, 341933083, 1090511722, 1432444805, 2522956527, 26662010075, 29184966602, 55846976677, 196725896633, 1039476459842, 3315155276159 (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 (0,0,0,0,0,0,0,3040,0,0,0,0,0,0,0,-1).

FORMULA

G.f.: -(x^14 -x^13 +2*x^12 -7*x^11 +37*x^10 -118*x^9 +155*x^8 -273*x^7 -155*x^6 -118*x^5 -37*x^4 -7*x^3 -2*x^2 -x -1) / (x^16 -3040*x^8 +1). - Colin Barker, Nov 12 2013

MATHEMATICA

Table[Denominator[FromContinuedFraction[ContinuedFraction[Sqrt[31], n]]], {n, 1, 50}] (* Vladimir Joseph Stephan Orlovsky, Mar 18 2011*)

Denominator[Convergents[Sqrt[31], 30]] (* Vincenzo Librandi, Dec 10 2013 *)

PROG

(MAGMA) I:=[1, 1, 2, 7, 37, 118, 155, 273, 2885, 3158, 6043, 21287, 112478, 358721, 471199, 829920]; [n le 16 select I[n] else 3040*Self(n-8) - Self(n-16): n in [1..50]]; // Vincenzo Librandi, Dec 10 2013

CROSSREFS

Cf. A041050, A010129, A020788, A010486.

Sequence in context: A173827 A029990 A042465 * A175487 A216362 A047066

Adjacent sequences:  A041048 A041049 A041050 * A041052 A041053 A041054

KEYWORD

nonn,cofr,easy,frac

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 12 2013

STATUS

approved

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Last modified November 16 03:09 EST 2018. Contains 317252 sequences. (Running on oeis4.)