login
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, 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
OFFSET
0,1
COMMENTS
Row sums are A174296. A181654 is an eigentriangle.
EXAMPLE
Triangle begins
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;
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
KEYWORD
easy,nonn,tabl
AUTHOR
Paul Barry, Nov 03 2010
STATUS
approved