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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.

A130405 Triangle where g.f. of row n = Product_{i=0..n} [F(i+1) + F(i)*x] for n>=0, where F(i) = A000045(i) is the i-th Fibonacci number.

Original entry on oeis.org

1, 1, 1, 2, 3, 1, 6, 13, 9, 2, 30, 83, 84, 37, 6, 240, 814, 1087, 716, 233, 30, 3120, 12502, 20643, 18004, 8757, 2254, 240, 65520, 303102, 596029, 646443, 417949, 161175, 34342, 3120, 2227680, 11681388, 26630128, 34495671, 27785569, 14256879
Offset: 0

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Author

Paul D. Hanna, May 24 2007

Keywords

Comments

First column equals A003266, the product of the first n nonzero Fibonacci numbers. Main diagonal and row sums are shifted forms of A003266.

Examples

			G.f. of row n = (1)(1+x)(2+x)(3+2x)(5+3x)*...*[F(n+1) + F(n)*x]:
row 3 g.f.: (1+x)(2+x)(3+2x) = 6 + 13x + 9x^2 + 2x^3;
row 4 g.f.: (1+x)(2+x)(3+2x)(5+3x) = 30 + 83x + 84x^2 + 37x^3 + 6x^4.
Triangle begins:
1;
1, 1;
2, 3, 1;
6, 13, 9, 2;
30, 83, 84, 37, 6;
240, 814, 1087, 716, 233, 30;
3120, 12502, 20643, 18004, 8757, 2254, 240;
65520, 303102, 596029, 646443, 417949, 161175, 34342, 3120;
...
Row vectors equal the product of flipped submatrices of Pascal's triangle;
for example, row vector 3 is equal to the matrix product:
[1 0 0 0] [1 1 0 0] [1 2 1 0] [1 3 3 1] = [6 13 9 2];
[0 0 0 0] [1 0 0 0] [1 1 0 0] [1 2 1 0]
[0 0 0 0] [0 0 0 0] [1 0 0 0] [1 1 0 0]
[0 0 0 0] [0 0 0 0] [0 0 0 0] [1 0 0 0]
likewise, row 4 may be obtained by the product:
[6 13 9 2 0] * [1 4 6 4 1] = [30 83 84 37 6] .
............. [1 3 3 1 0]
............. [1 2 1 0 0]
............. [1 1 0 0 0]
............. [1 0 0 0 0]
		

Crossrefs

Cf. A130406 (column 0), A130407 (diagonal); A003266, A000045.

Programs

  • PARI
    {T(n,k)=polcoeff(prod(i=0,n,round((fibonacci(i+1)+x*fibonacci(i)))),k)}