OFFSET
0,5
EXAMPLE
Triangle begins:
1;
-1,1;
-1,-2,1;
-7,-4,-3,1;
-77,-26,-9,-4,1;
-1145,-287,-67,-16,-5,1;
-21410,-4412,-798,-139,-25,-6,1;
-481683,-86004,-13029,-1830,-251,-36,-7,1; ...
PROG
(PARI) {T(n, k)=(matrix(n+1, n+1, r, c, if(r>=c, binomial((r-1)*(r-2)/2-(c-1)*(c-2)/2+r-c, r-c)))^-1)[n+1, k+1]}
CROSSREFS
KEYWORD
sign,tabl
AUTHOR
Paul D. Hanna, Jun 04 2005
STATUS
approved