A181652 Inverse of number triangle A181651.

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

Offset: 0

Author

Paul Barry, Nov 03 2010

Keywords

• easy
• sign
• tabl

Comments

Generalized (conditional) Riordan array with k-th column generated by x^k*if(mod(k,2)=0,(1-2x)/(1-x),1-x).

Examples

			Triangle begins
1,
-1, 1,
-1, -1, 1,
-1, 0, -1, 1,
-1, 0, -1, -1, 1,
-1, 0, -1, 0, -1, 1,
-1, 0, -1, 0, -1, -1, 1,
-1, 0, -1, 0, -1, 0, -1, 1,
-1, 0, -1, 0, -1, 0, -1, -1, 1,
-1, 0, -1, 0, -1, 0, -1, 0, -1, 1,
-1, 0, -1, 0, -1, 0, -1, 0, -1, -1, 1
Production matrix begins
-1, 1,
0, -2, 1,
1, 0, -2, 1,
1, -1, 0, -2, 1,
2, -1, 1, 0, -2, 1,
2, -1, 1, -1, 0, -2, 1,
3, -1, 2, -1, 1, 0, -2, 1,
3, -1, 2, -1, 1, -1, 0, -2, 1,
4, -1, 3, -1, 2, -1, 1, 0, -2, 1
		

Crossrefs

Cf. A070909.