A181653 - OEIS

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A181653

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

1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

0,1

COMMENTS

Row sums are A174296. A181654 is an eigentriangle.

LINKS

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

EXAMPLE

Triangle begins

1, 1;

0, 1, 1;

0, 1, 1, 1;

0, 0, 0, 1, 1;

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

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

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

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

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

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

Production matrix begins

1, 1;

-1, 0, 1;

1, 1, 0, 1;

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

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

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

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

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

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

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

CROSSREFS

Sequence in context: A163806 A163810 A163804 * A343159 A155091 A145362

Adjacent sequences: A181650 A181651 A181652 * A181654 A181655 A181656

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry, Nov 03 2010

STATUS

approved