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.

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A039762 Triangle of D-analogs of Stirling numbers of first kind.

Original entry on oeis.org

1, 0, 1, 1, -2, 1, -6, 11, -6, 1, 45, -84, 50, -12, 1, -420, 809, -520, 150, -20, 1, 4725, -9390, 6439, -2100, 355, -30, 1, -62370, 127539, -92358, 33019, -6510, 721, -42, 1, 945945, -1984584, 1505524, -578984, 127694, -16856, 1316, -56, 1, -16216200, 34812945, -27491616, 11228300, -2702448, 405174, -38304, 2220, -72, 1
Offset: 0

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Author

Ruedi Suter (suter(AT)math.ethz.ch)

Keywords

Examples

			Triangle T(n,k) (with rows n >= 0 and columns k = 0..n) begins:
     1;
     0,   1;
     1,  -2,    1;
    -6,  11,   -6,   1;
    45, -84,   50, -12,   1;
  -420, 809, -520, 150, -20, 1;
  ...
		

Crossrefs

Cf. A039757, A039758, A039763 (transposed triangle).

Programs

  • PARI
    row(n) = if(n==0, [1], Vecrev(prod(i=1, n-1, x-2*i+1)*(x-n+1))); \\ Petros Hadjicostas, Jul 12 2020

Formula

From Petros Hadjicostas, Jul 11 2020: (Start)
T(n,k) = [x^k] (x - (n - 1)) * Product_{k=1..n-1} (x - (2*k - 1)) for n >= 1 with T(0,0) = 1. (Empty products equal 1.)
Let R(n,k) = A039757(n,k) = A039758(n,n-k). Then, for n >= 1:
T(n,0) = -(n - 1)*R(n-1,0);
T(n,k) = R(n-1,k-1) - (n - 1)*R(n-1,k) for k = 1..n-1;
T(n,n) = R(n-1, n-1) = 1.
As a result, for n >= 2, T(n,0) = (-1)^n*(n-1)*(2*n-3)!!. (End)

Extensions

More terms from Petros Hadjicostas, Jul 12 2020
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