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.

A158442 Triangle T(n,k) = [x^k] n!*(n+1+x^n)*Sum_{i=0..n-1} x^i/(i+1).

Original entry on oeis.org

2, 1, 6, 3, 2, 1, 24, 12, 8, 6, 3, 2, 120, 60, 40, 30, 24, 12, 8, 6, 720, 360, 240, 180, 144, 120, 60, 40, 30, 24, 5040, 2520, 1680, 1260, 1008, 840, 720, 360, 240, 180, 144, 120, 40320, 20160, 13440, 10080, 8064, 6720, 5760, 5040, 2520, 1680, 1260, 1008, 840, 720, 362880
Offset: 1

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Author

Paul Curtz, Mar 19 2009

Keywords

Comments

The coefficient in front of x^k of the polynomial n!*(n+1+x^n)*Sum_{i=0..n-1} x^i/(i+1), columns k=0..2n-1.

Examples

			The triangle starts
    2,  1;
    6,  3,  2,  1;
   24, 12,  8,  6,  3,  2;
  120, 60, 40, 30, 24, 12,  8,  6;
		

Crossrefs

Cf. A130679 (table Q), A158442.

Programs

  • Maple
    P := proc(n,k) (n+1+x^n)*add( x^i/(i+1),i=0..n-1) ; coeftayl(expand(%),x=0,k) ; end:
    T := proc(n,k) n!*P(n,k) ; end:
    for n from 1 to 10 do for k from 0 to 2*n-1 do printf("%d,",T(n,k)) ; od: od: # R. J. Mathar, Apr 09 2009

Formula

Row sums: (n+2)*A000254(n).

Extensions

Edited by R. J. Mathar, Apr 09 2009