A155052 Image of symmetric Catalan based triangle A155050 under ((1+x)/(1-x),x)^{-1}.

1, -1, 1, 1, -1, 1, -1, 1, -1, 1, 1, -1, 2, -1, 1, -1, 1, -2, 2, -1, 1, 1, -1, 2, 1, 2, -1, 1, -1, 1, -2, -1, 1, 2, -1, 1, 1, -1, 2, 1, 8, 1, 2, -1, 1, -1, 1, -2, -1, -8, 8, 1, 2, -1, 1, 1, -1, 2, 1, 8, 20, 8, 1, 2, -1, 1

Offset: 0

Author

Paul Barry, Jan 19 2009

Keywords

• sign
• tabl

Comments

Row sums are aerated Catalan numbers (A000108).

Examples

			Triangle begins
1,
-1, 1,
1, -1, 1,
-1, 1, -1, 1,
1, -1, 2, -1, 1,
-1, 1, -2, 2, -1, 1,
1, -1, 2, 1, 2, -1, 1,
-1, 1, -2, -1, 1, 2, -1, 1,
1, -1, 2, 1, 8, 1, 2, -1, 1,
-1, 1, -2, -1, -8, 8, 1, 2, -1, 1,
1, -1, 2, 1, 8, 20, 8, 1, 2, -1, 1