This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A131756 Period 3: repeat [2, -1, 3]. 1
 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3, 2, -1, 3 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Index entries for linear recurrences with constant coefficients, signature (0,0,1). FORMULA a(n) = (1/9)*{7*(n mod 3)-8*[(n+1) mod 3]+13*[(n+3) mod 3]}. - Paolo P. Lava, Oct 08 2007 a(n) = 4/3+2/3*cos(2/3*Pi*n)-4/3*3^(1/2)*sin(2/3*Pi*n). - R. J. Mathar, Nov 15 2007 G.f.: (2-x+3*x^2)/(1-x^3). - Jaume Oliver Lafont, Mar 24 2009 a(n) = a(n-3) for n>2. - Wesley Ivan Hurt, Jul 01 2016 MAPLE seq(op([2, -1, 3]), n=0..50); # Wesley Ivan Hurt, Jul 01 2016 MATHEMATICA PadRight[{}, 100, {2, -1, 3}] (* Wesley Ivan Hurt, Jul 01 2016 *) PROG (PARI) a(n)=[2, -1, 3][1+n%3] \\ Jaume Oliver Lafont, Mar 24 2009 (MAGMA) &cat [[2, -1, 3]^^30]; // Wesley Ivan Hurt, Jul 01 2016 CROSSREFS Cf. A130784. Sequence in context: A118123 A181743 A174737 * A212620 A194859 A194838 Adjacent sequences:  A131753 A131754 A131755 * A131757 A131758 A131759 KEYWORD sign,easy AUTHOR Paul Curtz, Oct 04 2007 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.