OFFSET
0,2
FORMULA
Column k has g.f. (sum{j=0..k-1, C(k-1, j)C(j)x^(2j)/(1-4x)^(j+1/2)}+0^k*(1-2x-sqrt(1-4x))/(2x^2))(x/(1-x))^k
EXAMPLE
Triangle begins
1;
2,1;
5,3,1;
14,9,4,1;
42,29,14,5,1;
132,99,50,20,6,1;
CROSSREFS
KEYWORD
AUTHOR
Paul Barry, Apr 22 2005
STATUS
approved