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.

A194001 Mirror of the triangle A194000.

Original entry on oeis.org

1, 3, 2, 9, 5, 3, 24, 15, 8, 5, 64, 39, 24, 13, 8, 168, 104, 63, 39, 21, 13, 441, 272, 168, 102, 63, 34, 21, 1155, 714, 440, 272, 165, 102, 55, 34, 3025, 1869, 1155, 712, 440, 267, 165, 89, 55, 7920, 4895, 3024, 1869, 1152, 712, 432, 267, 144, 89, 20736
Offset: 0

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Author

Clark Kimberling, Aug 11 2011

Keywords

Comments

A194001 is obtained by reversing the rows of the triangle A194000.
Here, we extend of the conjecture begun at A194000. Suppose n is an odd positive integer and r(n+1,x) is the polynomial matched to row n+1 of A194001 as in the Mathematica program, where the first row is counted as row 0.
Conjecture: r(n+1,x) is the product of the following two polynomials whose coefficients are Fibonacci numbers:
linear factor: F(n+2)+x*F(n+3)
other: F(2)+F(4)*x^2+F(6)*x^4+...+F(n+1)*x^(n-1).
Example, for n=5:
r(6,x)=168*x^5+104*x^4+63*x^3+39^x^2+21*x+13 factors as
13+21x times 1+3x^2+8x^4.

Examples

			First six rows:
1
3....2
9....5....3
21...13...7....4
41...28...17...9....5
71...52...35...21...11...6
		

Crossrefs

Programs

  • Mathematica
    z = 11;
    p[n_, x_] := Sum[Fibonacci[k + 1]*x^(n - k), {k, 0, n}];
    q[n_, x_] := p[n, x];
    p1[n_, k_] := Coefficient[p[n, x], x^k];
    p1[n_, 0] := p[n, x] /. x -> 0;
    d[n_, x_] := Sum[p1[n, k]*q[n - 1 - k, x], {k, 0, n - 1}]
    h[n_] := CoefficientList[d[n, x], {x}]
    TableForm[Table[Reverse[h[n]], {n, 0, z}]]
    Flatten[Table[Reverse[h[n]], {n, -1, z}]]  (* A194000 *)
    TableForm[Table[h[n], {n, 0, z}]]
    Flatten[Table[h[n], {n, -1, z}]]  (* A194001 *)

Formula

Write w(n,k) for the triangle at A194000. The triangle at A194001 is then given by w(n,n-k).