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

0,1

Comments

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

Links

Table of n, a(n) for n=0..65.

Example

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.

Sequence in context: A141646 A129573 A330887 * A071024 A337263 A071037

Adjacent sequences: A181649 A181650 A181651 * A181653 A181654 A181655

Keyword

easy,sign,tabl

Author

Paul Barry, Nov 03 2010

Status

approved