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A041507 Denominators of continued fraction convergents to sqrt(270). 2
1, 2, 7, 44, 139, 322, 10443, 21208, 74067, 465610, 1470897, 3407404, 110507825, 224423054, 783776987, 4927084976, 15565031915, 36057148806, 1169393793707, 2374844736220, 8293928002367, 52138412750422, 164709166253633, 381556745257688 (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 (0,0,0,0,0,10582,0,0,0,0,0,-1).

FORMULA

G.f.: -(x^10 -2*x^9 +7*x^8 -44*x^7 +139*x^6 -322*x^5 -139*x^4 -44*x^3 -7*x^2 -2*x -1) / ((x^4 -22*x^2 +1)*(x^8 +22*x^6 +483*x^4 +22*x^2 +1)). - Colin Barker, Nov 18 2013

a(n) = 10582*a(n-6) - a(n-12) for n>11. - Vincenzo Librandi, Dec 19 2013

MATHEMATICA

Denominator[Convergents[Sqrt[270], 30]] (* Vincenzo Librandi, Dec 19 2013 *)

PROG

(MAGMA) I:=[1, 2, 7, 44, 139, 322, 10443, 21208, 74067, 465610, 1470897, 3407404]; [n le 12 select I[n] else 10582*Self(n-6)-Self(n-12): n in [1..30]]; // Vincenzo Librandi, Dec 19 2013

CROSSREFS

Cf. A041506, A040253.

Sequence in context: A270348 A270580 A103084 * A158107 A145073 A111561

Adjacent sequences:  A041504 A041505 A041506 * A041508 A041509 A041510

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 18 2013

STATUS

approved

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Last modified March 19 13:08 EDT 2019. Contains 321330 sequences. (Running on oeis4.)