OFFSET
0,13
FORMULA
Column k has g.f. (x^k/(1-x))*sum{j=0..k, C(k,2j)*2^j*(x/(1-x))^(2j)}
EXAMPLE
Triangle begins
1,
1, 1,
1, 1, 1,
1, 1, 1, 1,
1, 1, 3, 1, 1,
1, 1, 7, 7, 1, 1,
1, 1, 13, 19, 13, 1, 1,
1, 1, 21, 37, 37, 21, 1, 1
CROSSREFS
KEYWORD
AUTHOR
Paul Barry, May 14 2006
STATUS
approved