cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Previous Showing 21-22 of 22 results.

A144110 Period 6: repeat [2, 2, 2, 1, 1, 1].

Original entry on oeis.org

2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1
Offset: 0

Views

Author

Philippe Deléham, Sep 11 2008, Sep 15 2008

Keywords

Comments

a(n) = 2 for n = 0,1,2 modulo 6; a(n) = 1 for n = 3,4,5 modulo 6.

Crossrefs

Programs

Formula

G.f.: (1+2*x^3)/((1-x)*(1+x)*(1-x+x^2)); a(n) = 3/2-(-1)^n/6-A057079(n)/3. [R. J. Mathar, Sep 17 2008]
a(n) = a(n-1) - a(n-3) + a(n-4) for n>3; a(n) = 1 + mod(floor((-n-1)/3), 2); a(n) = A088911(n) + 1. - Wesley Ivan Hurt, Sep 04 2014
a(n) = (9 + cos(n*Pi) + 2*cos(n*Pi/3) + 2*sqrt(3)*sin(n*Pi/3))/6. - Wesley Ivan Hurt, Jun 23 2016

A133409 Zero followed by partial sums of A133405.

Original entry on oeis.org

0, 0, 0, 0, 1, 4, 13, 39, 117, 351, 1054, 3163, 9490, 28470, 85410, 256230, 768691, 2306074, 6918223, 20754669, 62264007, 186792021, 560376064, 1681128193, 5043384580, 15130153740, 45390461220, 136171383660
Offset: 0

Views

Author

Paul Curtz, Nov 25 2007

Keywords

Crossrefs

Programs

  • Mathematica
    Join[{0},Accumulate[LinearRecurrence[{3,0,-1,3},{0,0,0,1},40]]] (* or *) LinearRecurrence[{4,-3,-1,4,-3},{0,0,0,0,1},40] (* Harvey P. Dale, Dec 24 2013 *)

Formula

a(n+1)-3*a(n) = A088911(n+3).
a(n) = 4*a(n-1)-3*a(n-2)-a(n-3)+4*a(n-4)-3*a(n-5).
O.g.f.: x^4/((3*x-1)*(1+x)*(x^2-x+1)*(x-1)). - R. J. Mathar, Jul 16 2008

Extensions

Edited and extended by R. J. Mathar, Jul 16 2008
Previous Showing 21-22 of 22 results.