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

0,2

Comments

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

Links

Table of n, a(n) for n=0..65.

Formula

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

Example

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

Crossrefs

Sequence in context: A340262 A346369 A127569 * A127570 A340583 A292506

Adjacent sequences: A117369 A117370 A117371 * A117373 A117374 A117375

Keyword

easy,sign,tabl

Author

Paul Barry, Mar 10 2006

Status

approved