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.

A321044 Irregular table related to f[(a*x+b)/(c*x+d)]=(c*x+d)^(2*n)*f[x], and f[x]=1/(x+1), f[x]=(a*x+b)/(c*x+d).

Original entry on oeis.org

1, 1, 1, 1, 5, 4, 1, 1, 9, 16, 14, 6, 1, 1, 13, 36, 55, 50, 27, 8, 1, 1, 17, 64, 140, 196, 182, 112, 44, 10, 1, 1, 21, 100, 285, 540, 714, 672, 450, 210, 65, 12, 1, 1, 25, 144, 506, 1210, 2079, 2640, 2508, 1782, 935, 352, 90, 14, 1, 1, 29, 196, 819, 2366, 5005, 8008, 9867, 9438, 7007
Offset: 0

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Author

Roger L. Bagula, Oct 26 2018

Keywords

Comments

The author writes: This derivation is an interesting Fibonacci modular form. The modular form function is: f[(a*x+b)/(c*x+d)] = (c*x+d)^(2*n)*f[x] and I have used f[x]=1/(x+1) and f[x]=(a*x+b)/(c*x+d) for Möbius function matrix: {{0,1},{1,1}}. The polynomial is solved as a zero based form.
The graph of the root structures of the polynomial are mostly on a circle with center at -1, see Mathematica.

Examples

			{{1},
{1, 1},
{1, 5, 4, 1},
{1, 9, 16, 14, 6, 1},
{1, 13, 36, 55, 50, 27, 8,  1},
{1, 17, 64, 140, 196, 182, 112, 44, 10, 1},
{1, 21, 100, 285, 540, 714, 672, 450, 210, 65, 12, 1},
{1, 25, 144, 506, 1210, 2079, 2640, 2508, 1782,  935, 352, 90, 14, 1},
{1, 29, 196, 819, 2366, 5005, 8008, 9867, 9438, 7007, 4004, 1729, 546, 119, 16, 1},
{1, 33, 256, 1240, 4200, 10556, 20384, 30888,37180, 35750, 27456, 16744, 8008, 2940, 800, 152, 18, 1},
{1, 37, 324, 1785,6936, 20196, 45696, 82212, 119340, 140998, 136136, 107406, 68952, 35700, 14688, 4692, 1122, 189, 20, 1}}
		

Programs

  • Mathematica
    g[x_, n_] = If[n == 0, 1, (2 + x)*(1 + x)^(-1 + 2 n)/(1 + x) - 1]
    Show[Table[ListPlot[{Re[x], Im[x]} /. NSolve[g[x, n] == 0, x], PlotStyle -> Red], {n, 1, 10}]]
    a = Table[CoefficientList[g[x, n], x], {n, 0, 10}] (* Roger L. Bagula, Oct 26 2018 *)
    row[n_] = If[n > 0, CoefficientList[(x+2)*(x+1)^(2n-2)-1, x], {1}]; (* Charles R Greathouse IV, Oct 30 2018 *)
  • PARI
    row(n)=if(n, Vec((x+2)*(x+1)^(2*n-2)-1), [1]) \\ Charles R Greathouse IV, Oct 30 2018

Formula

For n > 0, the n-th row sum is 3*2^(2n-2) - 1. - Charles R Greathouse IV, Oct 30 2018