OFFSET
0,5
FORMULA
G.f.:(2x^6*y^2+x^5*y(2-y)+4x^4(1-y)-x^3(2y^2-3y+4)+x^2*y(y-2)+x(y-1)+1)/((1-4x^3)(1-x^3*y^3))
EXAMPLE
Triangle begins
1,
-1, 1,
0, -2, 1,
0, 3, -2, 1,
0, 0, 0, -1, 1,
0, -6, 3, 0, -2, 1,
0, 12, -6, 0, 3, -2, 1,
0, 0, 0, 0, 0, 0, -1, 1,
0, -24, 12, 0, -6, 3, 0, -2, 1,
0, 48, -24, 0, 12, -6, 0, 3, -2, 1
CROSSREFS
KEYWORD
AUTHOR
Paul Barry, Apr 01 2006
STATUS
approved