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.

A375047 Irregular triangular array T; row n shows the coefficients of the (n-1)-st polynomial in the obverse convolution s(x)**t(x), where s(x) = x+1 and t(x) = F(n) = n-th Fibonacci number. See Comments.

Original entry on oeis.org

1, 1, 2, 3, 1, 4, 8, 5, 1, 12, 28, 23, 8, 1, 48, 124, 120, 55, 12, 1, 288, 792, 844, 450, 127, 18, 1, 2592, 7416, 8388, 4894, 1593, 289, 27, 1, 36288, 106416, 124848, 76904, 27196, 5639, 667, 41, 1, 798336, 2377440, 2853072, 1816736, 675216, 151254, 20313
Offset: 1

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Author

Clark Kimberling, Sep 15 2024

Keywords

Comments

See A374848 for the definition of obverse convolution and a guide to related sequences and arrays.

Examples

			First 3 polynomials in s(x)**t(x) are
1 + x,
2 + 3 x + x^2,
4 + 8 x + 5 x^2 + x^3.
First 5 rows of array:
 1    1
 2    3    1
 4    8    5   1
12   28   23   8   1
48  124  120  55  12  1
		

Crossrefs

Programs

  • Mathematica
    s[n_] := x + 1; t[n_] := Fibonacci[n];
    u[n_] := Product[s[k] + t[n - k], {k, 0, n}]
    Table[Expand[u[n]], {n, 0, 10}]
    Column[Table[CoefficientList[Expand[u[n]], x], {n, 0, 10}]]   (* array *)
    Flatten[Table[CoefficientList[Expand[u[n]], x], {n, 0, 10}]]  (* sequence *)