OFFSET
0,2
FORMULA
Number triangle T(n, k)=2^k*binomial(2(n-k), n-k); Column k has g.f. (2x)^k/sqrt(1-4x).
EXAMPLE
Triangle begins
1;
2,2;
6,4,4;
20,12,8,8;
70,40,24,16,16;
CROSSREFS
KEYWORD
AUTHOR
Paul Barry, Sep 04 2005
STATUS
approved