OFFSET
0,2
FORMULA
Number triangle where column k has g.f. (1+x)^3*(k+1)x^k.
EXAMPLE
Triangle begins
1;
3, 2;
3, 6, 3;
1, 6, 9, 4;
0, 2, 9, 12, 5;
0, 0, 3, 12, 15, 6;
0, 0, 0, 4, 15, 18, 7;
0, 0, 0, 0, 5, 18, 21, 8;
CROSSREFS
KEYWORD
AUTHOR
Paul Barry, Oct 14 2005
STATUS
approved