OFFSET
0,9
FORMULA
T(n,n)=1, T(n+1,n)=n.
G.f.: (1-x*y+x^2*y)/(1-x*y)^2. - Philippe Deléham, Oct 31 2011
Sum_{k=0..n} T(n,k)*x^k = A000007(n), A028310(n), A057711(n+1), A064017(n+1) for x = 0, 1, 2, 3 respectively. - Philippe Deléham, Oct 31 2011
EXAMPLE
Triangle begins:
1;
0, 1;
0, 1, 1;
0, 0, 2, 1;
0, 0, 0, 3, 1;
0, 0, 0, 0, 4, 1;
0, 0, 0, 0, 0, 5, 1;
0, 0, 0, 0, 0, 0, 6, 1;
0, 0, 0, 0, 0, 0, 0, 7, 1;
0, 0, 0, 0, 0, 0, 0, 0, 8, 1;
0, 0, 0, 0, 0, 0, 0, 0, 0, 9, 1; ...
CROSSREFS
KEYWORD
AUTHOR
Philippe Deléham, Oct 28 2011
STATUS
approved