A119302 Inverse of number triangle binomial(3n-k,n-k).

1, -3, 1, 0, -5, 1, 0, 7, -7, 1, 0, -3, 18, -9, 1, 0, 0, -22, 33, -11, 1, 0, 0, 13, -65, 52, -13, 1, 0, 0, -3, 75, -140, 75, -15, 1, 0, 0, 0, -51, 238, -255, 102, -17, 1, 0, 0, 0, 19, -266, 570, -418, 133, -19, 1, 0, 0, 0, -3, 196, -882, 1155, -637, 168, -21, 1

Offset: 0

Author

Paul Barry, May 13 2006

Keywords

• easy
• sign
• tabl

Comments

Row sums are A119303. Inverse of A119301.

Examples

			Triangle begins
1,
-3, 1,
0, -5, 1,
0, 7, -7, 1,
0, -3, 18, -9, 1,
0, 0, -22, 33, -11, 1,
0, 0, 13, -65, 52, -13, 1,
0, 0, -3, 75, -140, 75, -15, 1
		

Formula

Riordan array (1-3x,x(1-x)^2); Number triangle T(n,k)=(C(2k,n-k)+3*C(2k,n-k-1))(-1)^(n-k).