A041765 - OEIS

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A041765

Denominators of continued fraction convergents to sqrt(403).

1, 13, 27, 40, 147, 187, 708, 895, 2498, 33369, 1337258, 17417723, 36172704, 53590427, 196943985, 250534412, 948547221, 1199081633, 3346710487, 44706317964, 1791599429047, 23335498895575, 48462597220197, 71798096115772, 263856885567513, 335654981683285

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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, 0, 0, 1339756, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).

FORMULA

G.f.: -(x^18 -13*x^17 +27*x^16 -40*x^15 +147*x^14 -187*x^13 +708*x^12 -895*x^11 +2498*x^10 -33369*x^9 -2498*x^8 -895*x^7 -708*x^6 -187*x^5 -147*x^4 -40*x^3 -27*x^2 -13*x -1) / (x^20 -1339756*x^10 +1). - Colin Barker, Nov 24 2013

a(n) = 1339756*a(n-10) - a(n-20) for n>19. - Vincenzo Librandi, Dec 24 2013

MATHEMATICA

Denominator[Convergents[Sqrt[403], 30]] (* Vincenzo Librandi, Dec 24 2013 *)

CROSSREFS

Cf. A041764, A040382.

Sequence in context: A251149 A293787 A041330 * A041328 A136773 A358053

Adjacent sequences: A041762 A041763 A041764 * A041766 A041767 A041768

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Nov 24 2013

STATUS

approved