A117372 Riordan array (1-3x,x(1-x)).

1, -3, 1, 0, -4, 1, 0, 3, -5, 1, 0, 0, 7, -6, 1, 0, 0, -3, 12, -7, 1, 0, 0, 0, -10, 18, -8, 1, 0, 0, 0, 3, -22, 25, -9, 1, 0, 0, 0, 0, 13, -40, 33, -10, 1, 0, 0, 0, 0, -3, 35, -65, 42, -11, 1, 0, 0, 0, 0, 0, -16, 75, -98, 52, -12, 1

Offset: 0

Author

Paul Barry, Mar 10 2006

Keywords

• easy
• sign
• tabl

Comments

Row sums are A117373. Diagonal sums are A117374. Inverse is A117375.

Examples

			Triangle begins
1,
-3, 1,
0, -4, 1,
0, 3, -5, 1,
0, 0, 7, -6, 1,
0, 0, -3, 12, -7, 1,
0, 0, 0, -10, 18, -8, 1,
0, 0, 0, 3, -22, 25, -9, 1
		

Formula

Number triangle T(n,k)=(-1)^(n-k)(C(k,n-k)+3*C(k, n-k-1))