OFFSET
0,4
FORMULA
T(n,k)=2*T(n-1,k)+T(n-1,k-1)-T(n-2,k-1), for n>2.
T(n,0)=-2^(n-1) for n>0.
T(2*n,n)=A047781(n) for n>0.
T(n,1)=(4-n)*2^(n-3) for n>1.
G.f.: (1-3*x+x^2*y)/(1-2*x+x^2*y-x*y). - R. J. Mathar, Aug 11 2015
EXAMPLE
Triangle begins :
1
-1, 1
-2, 1, 1
-4, 1, 2, 1
-8, 0, 4, 3, 1
-16, -4, 7, 8, 4, 1
-32, -16, 10, 19, 13, 5, 1
-64, -48, 8, 41, 37, 19, 6, 1
-128, -128, -16, 80, 96, 62, 26, 7, 1
CROSSREFS
KEYWORD
sign,tabl
AUTHOR
Philippe Deléham, Nov 11 2011
STATUS
approved