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.

A144220 Triangle read by rows, A118433 (the self-inverse triangle) * A000012^(-1).

Original entry on oeis.org

1, 2, -1, -3, 1, 1, -4, 0, 4, -1, 5, 2, -10, 3, 1, 6, 5, -20, 5, 6, -1, -7, -9, 35, 5, -21, 5, 1, -8, -14, 56, 0, -56, 14, 8, -1, 9, 20, -84, -14, 126, -28, -36, 7, 1, 10, 27, -120, -42, 252, -42, -120, 27, 10, -1, -11, -35, 165, 90, -462, 42, 330, -75, -55, 9, 1
Offset: 0

Views

Author

Gary W. Adamson, Sep 14 2008

Keywords

Comments

Row sums = (1, 1, -1, -1, 1, 1, ...).

Examples

			First few rows of the triangle:
   1;
   2,  -1;
   3,   1,    1;
  -4,   0,    4,  -1
   5,   2,  -10,   3,   1;
   6,   5,  -20,   5,   6,  -1;
  -7,  -9,   35,  -5, -21,   5,    1;
  -8, -14,   56,   0, -56,  14,    8, -1;
   9,  20,  -84, -14, 126, -28,  -36,  7,  1;
  10,  27, -120, -42, 252, -42, -120, 27, 10, -1;
  ...
		

Crossrefs

Cf. A118433.

Formula

A118433 * A000012^(-1), where A000012^(-1) is an infinite lower triangular matrix with 1's in the main diagonal and (-1)'s in the subdiagonal, with the rest zeros.