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A181652 Inverse of number triangle A181651. 1
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 (list; table; graph; refs; listen; history; text; internal format)
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: A136705 A141646 A129573 * A071024 A071037 A118172

Adjacent sequences:  A181649 A181650 A181651 * A181653 A181654 A181655

KEYWORD

easy,sign,tabl

AUTHOR

Paul Barry, Nov 03 2010

STATUS

approved

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Last modified October 14 18:28 EDT 2019. Contains 328022 sequences. (Running on oeis4.)