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.

A220884 Triangle read by rows: row n gives coefficients of expansion of Product_{k=2..n} ((n+1-k)*x+k), starting with lowest power.

Original entry on oeis.org

1, 1, 2, 1, 6, 8, 2, 24, 58, 37, 6, 120, 444, 504, 204, 24, 720, 3708, 6388, 4553, 1318, 120, 5040, 33984, 81136, 87296, 44176, 9792, 720, 40320, 341136, 1064124, 1582236, 1203921, 463860, 82332, 5040, 362880, 3733920, 14602320, 28328480, 29724000, 17164320, 5270480, 773280, 40320, 3628800, 44339040, 210852936, 512539012, 700870638, 557061609, 255644668, 64621692, 8026416, 362880
Offset: 0

Views

Author

N. J. A. Sloane, Dec 29 2012

Keywords

Comments

Related to Stirling numbers A008275, A008277.

Examples

			Triangle begins:
[1]
[1]
[2, 1]
[6, 8, 2]
[24, 58, 37, 6]
[120, 444, 504, 204, 24]
[720, 3708, 6388, 4553, 1318, 120]
[5040, 33984, 81136, 87296, 44176, 9792, 720]
...
		

Crossrefs

Row sums give A000272(n+1).
Columns k=0-1 give A000142, A002538(n-1).

Programs

  • Maple
    T:= n-> (p-> seq(coeff(p, x, i), i=0..degree(p)))(
             expand(mul((n+1-k)*x+k, k=2..n))):
    seq(T(n), n=0..10);  # Alois P. Heinz, Nov 29 2015
  • Mathematica
    row[n_] := CoefficientList[Product[((n+1-k)*x+k), {k, 2, n}], x]; Table[ row[n], {n, 0, 10}] // Flatten (* Jean-François Alcover, Feb 17 2016 *)

Extensions

T(0,0)=1 prepended by Alois P. Heinz, Nov 29 2015