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.

A322044 Triangle read by rows: numerators of coefficients (highest degree first) of polynomials interpolating Fibonacci numbers.

Original entry on oeis.org

1, 1, 2, 1, 3, 6, 1, 3, 14, 30, 1, 2, 23, 94, 192, 1, 0, 35, 180, 744, 1560, 1, -3, 55, 255, 1744, 7308, 15120, 1, -7, 91, 245, 3304, 19922, 82284, 171360, 1, -12, 154, 0, 5929, 40572, 255996, 1068240, 2217600, 1, -18, 258, -756, 11361, 64638, 602972, 3746376, 15533568, 32296320
Offset: 0

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Author

N. J. A. Sloane, Dec 07 2018

Keywords

Comments

Row n has denominator n!.

Examples

			Triangle begins:
  1;
  1,  2;
  1,  3,  6;
  1,  3, 14,  30;
  1,  2, 23,  94,  192;
  1,  0, 35, 180,  744, 1560;
  1, -3, 55, 255, 1744, 7308, 15120;
  ...
		

References

  • Brian Hopkins and Aram Tangboonduangjit, Fibonacci-producing rational polynomials, Fib. Q., 56:4 (2018), 303-312.

Crossrefs

Main diagonal gives A078700(n+1).
Second column is negation of A167544.

Programs

  • Maple
    F:= proc(n) option remember; (<<0|1>, <1|1>>^n)[1, 2] end:
    T:= n-> (p-> seq(coeff(p, x, n-j), j=0..n))(n!*expand(add(
          F(i+n+2)*binomial(x, i)*binomial(n-x, n-i), i=0..n))):
    seq(T(n), n=0..10);  # Alois P. Heinz, Feb 24 2019
  • Mathematica
    F[n_] := F[n] = MatrixPower[{{0, 1}, {1, 1}}, n][[1, 2]];
    T[n_] := Function[p, Table[Coefficient[p, x, n - j], {j, 0, n}]][n! * FunctionExpand[Sum[F[i + n + 2] Binomial[x, i] Binomial[n - x, n - i], {i, 0, n}]]];
    T /@ Range[0, 10] // Flatten (* Jean-François Alcover, May 29 2020, after Alois P. Heinz *)

Formula

The degree n polynomial is defined to be the interpolating polynomial of (0, F(n+2)), (1, F(n+3)), ..., (n,F(2n+2)) where F(n) is the n-th Fibonacci number. Theorem 2.1 of the paper proves the alternative form Sum_{i=0..n} F(i+n+2) * binomial(x,i) * binomial(n-x,n-i). - Brian Hopkins, Feb 24 2019

Extensions

Edited by Brian Hopkins, Feb 24 2019