|
| |
|
|
A117362
|
|
Riordan array (1-2x,x(1-x)).
|
|
1
| |
|
|
1, -2, 1, 0, -3, 1, 0, 2, -4, 1, 0, 0, 5, -5, 1, 0, 0, -2, 9, -6, 1, 0, 0, 0, -7, 14, -7, 1, 0, 0, 0, 2, -16, 20, -8, 1, 0, 0, 0, 0, 9, -30, 27, -9, 1, 0, 0, 0, 0, -2, 25, -50, 35, -10, 1, 0, 0, 0, 0, 0, -11, 55, -77, 44, -11, 1
(list; table; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| A signed version of A113214. Inverse of A092392. Row sums are A100051(n+1) with g.f. (1-2x)/(1-x+x^2). Diagonal sums are A117363.
|
|
|
FORMULA
| Number triangle T(n,k)=(-1)^(n-k)(C(k,n-k)+2*C(k, n-k-1))
|
|
|
EXAMPLE
| Triangle begins
1,
-2, 1,
0, -3, 1,
0, 2, -4, 1,
0, 0, 5, -5, 1,
0, 0, -2, 9, -6, 1,
0, 0, 0, -7, 14, -7, 1,
0, 0, 0, 2, -16, 20, -8, 1
|
|
|
CROSSREFS
| Sequence in context: A130055 A202452 A127013 * A113214 A168016 A029323
Adjacent sequences: A117359 A117360 A117361 * A117363 A117364 A117365
|
|
|
KEYWORD
| easy,sign,tabl
|
|
|
AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Mar 10 2006
|
| |
|
|
