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.

A143091 a(n) = a(floor(2n/3)) + a(floor(n/3)) starting a(0)=a(1)=1.

Original entry on oeis.org

1, 1, 2, 3, 3, 4, 5, 5, 6, 8, 8, 8, 9, 9, 11, 12, 12, 12, 14, 14, 14, 16, 16, 17, 18, 18, 18, 22, 22, 22, 22, 22, 24, 24, 24, 25, 27, 27, 27, 27, 27, 31, 33, 33, 33, 34, 34, 34, 36, 36, 36, 36, 36, 37, 41, 41, 41, 41, 41, 41, 41, 41, 45, 49, 49, 49, 49, 49, 50, 51, 51, 51, 54, 54
Offset: 0

Views

Author

Roger L. Bagula, Oct 16 2008

Keywords

Programs

  • Maple
    A143091 := proc(n)
            option remember;
            if n <=1 then
                    1;
            else
                    procname(floor(n/3))+procname(floor(2*n/3)) ;
            end if;
    end proc: # R. J. Mathar, Jul 12 2012
  • Mathematica
    Clear[a, f, b, c, g] (*fractal noise chaotic sequence*) f[0] = 1; f[1] = 0; f[1] = 1; f[n_] := f[n] = f[n - f[n - 1]] + f[Floor[2*n/3]] (*Cantor like fractal stair step chaotic sequence*) g[0] = 1; g[1] = 0; g[1] = 1; g[n_] := g[n] = g[Floor[2*n/3]] + g[Floor[n/3]]; ListPlot[Table[{f[n], g[n]}, {n, 0, 200}], PlotJoined -> True]; Table[g[n], {n, 0, 200}]