login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A042701 Denominators of continued fraction convergents to sqrt(880). 2
1, 1, 2, 3, 176, 179, 355, 534, 31327, 31861, 63188, 95049, 5576030, 5671079, 11247109, 16918188, 992502013, 1009420201, 2001922214, 3011342415, 176659782284, 179671124699, 356330906983, 536002031682, 31444448744539, 31980450776221, 63424899520760 (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 (0,0,0,178,0,0,0,-1).

FORMULA

G.f.: -(x^2-x-1)*(x^4+3*x^2+1) / (x^8-178*x^4+1). - Colin Barker, Dec 21 2013

a(n) = 178*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Dec 21 2013

MATHEMATICA

Denominator[Convergents[Sqrt[880], 30]] (* Vincenzo Librandi Dec 21 2013 *)

LinearRecurrence[{0, 0, 0, 178, 0, 0, 0, -1}, {1, 1, 2, 3, 176, 179, 355, 534}, 30] (* Harvey P. Dale, Dec 09 2018 *)

PROG

(MAGMA) I:=[1, 1, 2, 3, 176, 179, 355, 534]; [n le 8 select I[n] else 178*Self(n-4)-Self(n-8): n in [1..70]]; // Vincenzo Librandi, Dec 21 2013

CROSSREFS

Cf. A042700, A040850.

Sequence in context: A115231 A042369 A328257 * A246488 A106715 A106817

Adjacent sequences:  A042698 A042699 A042700 * A042702 A042703 A042704

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Colin Barker, Dec 21 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 25 19:39 EST 2021. Contains 341618 sequences. (Running on oeis4.)