|
|
A204040
|
|
Triangle T(n,k), read by rows, given by (0, 2, -2, 1, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (1, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938.
|
|
0
|
|
|
1, 0, 1, 0, 2, 1, 0, 0, 4, 1, 0, -4, 4, 6, 1, 0, -4, -8, 12, 8, 1, 0, 4, -24, -4, 24, 10, 1, 0, 12, -8, -60, 16, 40, 12, 1, 0, 4, 56, -84, -96, 60, 60, 14, 1, 0, -20, 88, 84, -272, -100, 136, 84, 16, 1, 0, -28, -40
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,5
|
|
COMMENTS
|
Antidiagonal sums : periodic sequence 1, 0, 1, 2, 1, 0, 1, 2, 1, 0, 1, 2, ... (see A007877 or A098178).Riordan array (1, x*(1+x)/(1-x+2*x^2)) .
|
|
LINKS
|
|
|
FORMULA
|
T(n,k) = T(n-1,k) + T(n-1,k-1) + T(n-2, k-1) - 2*T(n-2,k).
G.f.: (1-x+2*x^2)/(1-(1+y)*x + (2-y)*x^2).
|
|
EXAMPLE
|
Triangle begins :
1
0, 1
0, 2, 1
0, 0, 4, 1
0, -4, 4, 6, 1
0, -4, -8, 12, 8, 1
0, 4, -24, -4, 24, 10, 1
0, 12, -8, -60, 16, 40, 12, 1
0, 4, 56, -84, -96, 60, 60, 14, 1
0, -20, 88, 84, -272, -100, 136, 84, 16, 1
|
|
CROSSREFS
|
|
|
KEYWORD
|
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|