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

 

Logo

The submissions stack has been unacceptably high for several months now. Please voluntarily restrict your submissions and please help with the editing. (We don't want to have to impose further limits.)

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A135447 Period 10: repeat 1, 2, 4, 8, 5, -1, -2, -4, -8, -5. 1
1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..83.

Index entries for linear recurrences with constant coefficients, signature (1,-1,1,-1).

FORMULA

a(n+1) == 2a(n) mod 11.

a(n)=(1/10)*{-6*(n mod 10)-3*[(n+1) mod 10]+4*[(n+2) mod 10]+2*[(n+3) mod 10]+[(n+4) mod 10]+6*[(n+5) mod 10]+3*[(n+6) mod 10]-4*[(n+7) mod 10]-2*[(n+8) mod 10]-[(n+9) mod 10]}, with n>=0. - Paolo P. Lava, Dec 18 2007

a(n) = (0.5-(7*5^0.5/10))*cos(Pi*n/5)+(2^0.5/10)*(12*(5+5^0.5)^0.5+7*(5-5^0.5)^0.5)*sin(Pi*n/5)+(0.5+(7*5^0.5/10))*cos(3*Pi*n/5)-(2^0.5/10)*(12*(5-5^0.5)^0.5-7*(5+5^0.5)^0.5)*sin(3*Pi*n/5). - Richard Choulet, Jan 04 2008

O.g.f.: (5*x^3+3*x^2+x+1)/(x^4-x^3+x^2-x+1) . - R. J. Mathar, Jan 07 2008

MAPLE

A135447 := proc(n) op((n mod 10)+1, [1, 2, 4, 8, 5, -1, -2, -4, -8, -5]) ; end: seq(A135447(n), n=0..150) ; [From R. J. Mathar, Feb 07 2009]

PROG

(PARI) a(n)=[1, 2, 4, 8, 5, -1, -2, -4, -8, -5][n%10+1] \\ Charles R Greathouse IV, Jun 02 2011

CROSSREFS

Sequence in context: A133992 A126215 A165617 * A163339 A092892 A146079

Adjacent sequences:  A135444 A135445 A135446 * A135448 A135449 A135450

KEYWORD

sign,easy,less

AUTHOR

Paul Curtz, Dec 14 2007

EXTENSIONS

More periods from R. J. Mathar, Feb 07 2009

STATUS

approved

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

Content is available under The OEIS End-User License Agreement .

Last modified August 27 17:19 EDT 2015. Contains 261095 sequences.