login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A042815 Denominators of continued fraction convergents to sqrt(938). 2
1, 1, 2, 3, 8, 67, 142, 209, 351, 560, 33951, 34511, 68462, 102973, 274408, 2298237, 4870882, 7169119, 12040001, 19209120, 1164587201, 1183796321, 2348383522, 3532179843, 9412743208, 78834125507, 167080994222 (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, 0, 0, 34302, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).

FORMULA

G.f.: -(x^18 -x^17 +2*x^16 -3*x^15 +8*x^14 -67*x^13 +142*x^12 -209*x^11 +351*x^10 -560*x^9 -351*x^8 -209*x^7 -142*x^6 -67*x^5 -8*x^4 -3*x^3 -2*x^2 -x -1) / (x^20 -34302*x^10 +1). - Colin Barker, Dec 24 2013

a(n) = 34302*a(n-10) - a(n-20) for n>19. - Vincenzo Librandi, Jan 30 2014

MATHEMATICA

Denominator[Convergents[Sqrt[938], 50]] (* Harvey P. Dale, Sep 16 2011 *)

PROG

(MAGMA) I:=[1, 1, 2, 3, 8, 67, 142, 209, 351, 560, 33951, 34511, 68462, 102973, 274408, 2298237, 4870882, 7169119, 12040001, 19209120]; [n le 20 select I[n] else 34302*Self(n-10)-Self(n-20): n in [1..30]]; // Vincenzo Librandi, Jan 30 2014

CROSSREFS

Cf. A042814, A040907.

Sequence in context: A072043 A095203 A003096 * A191353 A319218 A243954

Adjacent sequences:  A042812 A042813 A042814 * A042816 A042817 A042818

KEYWORD

nonn,frac,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Additional term from Colin Barker, Dec 24 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 April 20 04:42 EDT 2019. Contains 322294 sequences. (Running on oeis4.)