A181656 Generalized (conditional) Riordan array with k-th column generated by x^k*(1+x^2) if k mod 2 = 0, x^k*(1+x) otherwise.

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

Offset

0,1

Comments

A181657 is an eigentriangle for this triangle.

Links

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

Example

Triangle begins
  1;
  0, 1;
  1, 1, 1;
  0, 0, 0, 1;
  0, 0, 1, 1, 1;
  0, 0, 0, 0, 0, 1;
  0, 0, 0, 0, 1, 1, 1;
  0, 0, 0, 0, 0, 0, 0, 1;
  0, 0, 0, 0, 0, 0, 1, 1, 1;
  0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
  0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1;
Production matrix begins
   0,  1;
   1,  1,  1;
  -1, -2, -1,  1;
   0,  0,  1,  1,  1;
   1,  2,  0, -2, -1,  1;
   0,  0,  0,  0,  1,  1,  1;
  -1, -2,  0,  2,  0, -2, -1,  1;
   0,  0,  0,  0,  0,  0,  1,  1,  1;
   1,  2,  0, -2,  0,  2,  0, -2, -1,  1;
   0,  0,  0,  0,  0,  0,  0,  0,  1,  1,  1;

Crossrefs

Sequence in context: A191232 A267814 A267272 * A090971 A105594 A091949

Adjacent sequences: A181653 A181654 A181655 * A181657 A181658 A181659

Keyword

easy,nonn,tabl

Author

Paul Barry, Nov 03 2010

Status

approved