A117568 Riordan array ((1-x^3)/(1+x^2),x).

1, 0, 1, -1, 0, 1, -1, -1, 0, 1, 1, -1, -1, 0, 1, 1, 1, -1, -1, 0, 1, -1, 1, 1, -1, -1, 0, 1, -1, -1, 1, 1, -1, -1, 0, 1, 1, -1, -1, 1, 1, -1, -1, 0, 1, 1, 1, -1, -1, 1, 1, -1, -1, 0, 1, -1, 1, 1, -1, -1, 1, 1, -1, -1, 0, 1, -1, -1, 1, 1, -1, -1, 1, 1, -1, -1, 0, 1, 1, -1, -1, 1, 1, -1, -1, 1, 1, -1, -1, 0, 1

Offset: 0

Author

Paul Barry, Mar 29 2006

Keywords

• easy
• sign
• tabl

Comments

Inverse of number triangle A117567. Row sums are A117569. Diagonal sums are A102560.

Examples

			Triangle begins
1,
0, 1,
-1, 0, 1,
-1, -1, 0, 1,
1, -1, -1, 0, 1,
1, 1, -1, -1, 0, 1,
-1, 1, 1, -1, -1, 0, 1,
-1, -1, 1, 1, -1, -1, 0, 1,
1, -1, -1, 1, 1, -1, -1, 0, 1