A117377 Riordan array (1-4x,x(1-x)).

1, -4, 1, 0, -5, 1, 0, 4, -6, 1, 0, 0, 9, -7, 1, 0, 0, -4, 15, -8, 1, 0, 0, 0, -13, 22, -9, 1, 0, 0, 0, 4, -28, 30, -10, 1, 0, 0, 0, 0, 17, -50, 39, -11, 1, 0, 0, 0, 0, -4, 45, -80, 49, -12, 1, 0, 0, 0, 0, 0, -21, 95, -119, 60, -13, 1

Offset

0,2

Comments

Row sums are A117378. Diagonal sums are A117379. Inverse is A117380.

Links

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

Formula

Number triangle T(n,k)=(-1)^(n-k)(C(k,n-k)+4*C(k, n-k-1))

Example

Triangle begins
1,
-4, 1,
0, -5, 1,
0, 4, -6, 1,
0, 0, 9, -7, 1,
0, 0, -4, 15, -8, 1,
0, 0, 0, -13, 22, -9, 1,
0, 0, 0, 4, -28, 30, -10, 1

Crossrefs

Sequence in context: A110146 A303499 A108944 * A046784 A011349 A303126

Adjacent sequences: A117374 A117375 A117376 * A117378 A117379 A117380

Keyword

easy,sign,tabl

Author

Paul Barry, Mar 10 2006

Status

approved