A147750 Riordan array ((1-x-x^2)/(1-x-2x^2), x(1-x)/(1-2x)).

1, 0, 1, 1, 1, 1, 1, 3, 2, 1, 3, 6, 6, 3, 1, 5, 14, 15, 10, 4, 1, 11, 30, 38, 29, 15, 5, 1, 21, 66, 92, 81, 49, 21, 6, 1, 43, 142, 220, 216, 150, 76, 28, 7, 1, 85, 306, 516, 560, 435, 253, 111, 36, 8, 1

Offset: 0

Author

Paul Barry, Nov 11 2008

Keywords

• easy
• nonn
• tabl

Comments

Row sums are A061646. A147750=A007318^-1*A147747.

Examples

			Triangle begins
1,
0, 1,
1, 1, 1,
1, 3, 2, 1,
3, 6, 6, 3, 1,
5, 14, 15, 10, 4, 1,
11, 30, 38, 29, 15, 5, 1,
21, 66, 92, 81, 49, 21, 6, 1