A174302 Riordan array ((1-x^2c(x)^2)/(1-xc(x)-x^2c(x)^2),xc(x)), c(x) the g.f. of A000108.

1, 1, 1, 2, 2, 1, 6, 5, 3, 1, 19, 15, 9, 4, 1, 63, 48, 29, 14, 5, 1, 215, 160, 97, 49, 20, 6, 1, 749, 548, 333, 173, 76, 27, 7, 1, 2650, 1914, 1165, 617, 284, 111, 35, 8, 1, 9490, 6785, 4135, 2221, 1056, 439, 155, 44, 9, 1

Offset: 0

Author

Paul Barry, Mar 15 2010

Keywords

• easy
• nonn
• tabl

Comments

First row is essentially A109262.

Examples

			Triangle begins
1,
1, 1,
2, 2, 1,
6, 5, 3, 1,
19, 15, 9, 4, 1,
63, 48, 29, 14, 5, 1,
215, 160, 97, 49, 20, 6, 1,
749, 548, 333, 173, 76, 27, 7, 1,
Production matrix begins
1, 1,
1, 1, 1,
2, 1, 1, 1,
2, 1, 1, 1, 1,
3, 1, 1, 1, 1, 1,
3, 1, 1, 1, 1, 1, 1,
4, 1, 1, 1, 1, 1, 1, 1