A116949 - OEIS

A116949

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

1, 0, 1, -2, 0, 1, -1, -2, 0, 1, 4, -1, -2, 0, 1, 2, 4, -1, -2, 0, 1, -8, 2, 4, -1, -2, 0, 1, -4, -8, 2, 4, -1, -2, 0, 1, 16, -4, -8, 2, 4, -1, -2, 0, 1, 8, 16, -4, -8, 2, 4, -1, -2, 0, 1, -32, 8, 16, -4, -8, 2, 4, -1, -2, 0, 1, -16, -32, 8, 16, -4, -8, 2, 4, -1, -2, 0, 1, 64, -16, -32, 8, 16, -4, -8, 2, 4, -1, -2, 0, 1

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OFFSET

0,4

COMMENTS

Sequence array of (-2)^(n/2)(1+(-1)^n)/2-(-2)^((n-3)/2)(1-(-1)^n)/2-(comb(1,n)-comb(0,n))/2.

Inverse of A116948.

Row sums are A117575. Diagonal sums are A117576.

LINKS

Table of n, a(n) for n=0..90.

EXAMPLE

Number triangle begins

0, 1,

-2, 0, 1,

-1, -2, 0, 1,

4, -1, -2, 0, 1,

2, 4, -1, -2, 0, 1,

-8, 2, 4, -1, -2, 0, 1,

-4, -8, 2, 4, -1, -2, 0, 1,

16, -4, -8, 2, 4, -1, -2, 0, 1

CROSSREFS

Cf. A117575, A117576, A116948.

Sequence in context: A328342 A214269 A130027 * A359244 A204427 A178146

Adjacent sequences: A116946 A116947 A116948 * A116950 A116951 A116952

KEYWORD

easy,sign,tabl

AUTHOR

Paul Barry, Mar 29 2006

EXTENSIONS

Entry revised by N. J. A. Sloane, Apr 10 2006

STATUS

approved