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.

A270250 Triangle read by rows: coefficients of the polynomial (Sum_{i=0..k} (Product_{j=0..i} (x+j)))/(x*(x+2)).

Original entry on oeis.org

1, 2, 1, 5, 5, 1, 17, 24, 9, 1, 77, 131, 68, 14, 1, 437, 833, 529, 151, 20, 1, 2957, 6107, 4458, 1571, 290, 27, 1, 23117, 50819, 41164, 16860, 3870, 505, 35, 1, 204557, 473387, 416230, 191167, 51379, 8387, 819, 44, 1, 2018957, 4880507, 4589458, 2309303, 700776, 134716, 16541, 1258, 54, 1
Offset: 1

Views

Author

Michel Marcus, Mar 14 2016

Keywords

Comments

The lines offset is 1, but the columns offset is 0.

Examples

			First rows of this triangle:
   1;
   2,   1;
   5,   5,   1;
  17,  24,   9,   1;
  77, 131,  68,  14,   1;
  ...
		

Crossrefs

Cf. A007489 (values of polynomial when x=2), A014288 (first column).

Programs

  • PARI
    row(n) = Vecrev(sum(i=0, n, prod(j=0, i, x+j))/(x*(x+2)));