A128821 Triangle T(n,k), 1<=k<=n, read by rows defined by :T(n,k)=C(n,k)*C(n-1,k-1)+C(n,k-1)*C(n-1,k)where C(n,k)=A007318(n,k) .
1, 3, 1, 5, 9, 1, 7, 30, 18, 1, 9, 70, 100, 30, 1, 11, 135, 350, 250, 45, 1, 13, 231, 945, 1225, 525, 63, 1, 15, 364, 2156, 4410, 3430, 980, 84, 1, 17, 540, 4368, 12936, 15876, 8232, 1680, 108, 1, 19, 765, 8100, 32760, 58212, 47628, 17640, 2700, 135, 1
Offset: 1
Examples
Triangle begins: 1; 3, 1; 5, 9, 1; 7, 30, 18, 1; 9, 70, 100, 30, 1; 11, 135, 350, 250, 45, 1; 13, 231, 945, 1225, 525, 63, 1; 15, 364, 2156, 4410, 3430, 980, 84, 1 ;...