A115358 - OEIS

A115358

Inverse of matrix (1,x)+(x,x^2) (expressed in Riordan array notation).

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

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OFFSET

0,1

COMMENTS

Row sums are A035263 (first Feigenbaum symbolic (or period-doubling) sequence). Columns are signed stretched Fredholm-Rueppel sequences. Inverse is A115356.

LINKS

Table of n, a(n) for n=0..123.

FORMULA

Number triangle whose k-th column has g.f. x^k*sum{j>=0, (-1)^j*(x^(2j-1))^(k+1)}.

EXAMPLE

Triangle begins

-1, 1;

0, 0, 1;

1, -1, 0, 1;

0, 0, 0, 0, 1;

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

0, 0, 0, 0, 0, 0, 1;

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

0, 0, 0, 0, 0, 0, 0, 0, 1;

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

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;

CROSSREFS

Sequence in context: A016410 A230412 A115361 * A325898 A117904 A259030

Adjacent sequences: A115355 A115356 A115357 * A115359 A115360 A115361

KEYWORD

easy,sign,tabl

AUTHOR

Paul Barry, Jan 21 2006

STATUS

approved