OFFSET
0,2
FORMULA
Number triangle T(n, k)=(k-1)*C(k(n-k), n-k)-(k-2)*sum{j=0..n-k, C(k(n-k), j)}
EXAMPLE
Triangle begins
1;
2,1;
2,2,1;
2,4,2,1;
2,8,6,2,1;
2,16,20,8,2,1;
CROSSREFS
KEYWORD
AUTHOR
Paul Barry, May 09 2005
STATUS
approved