A117352 Riordan array (1/(1-2x), x(1-2x)/(1-x)).
1, 2, 1, 4, 1, 1, 8, 1, 0, 1, 16, 1, -1, -1, 1, 32, 1, -2, -2, -2, 1, 64, 1, -3, -2, -2, -3, 1, 128, 1, -4, -1, 0, -1, -4, 1, 256, 1, -5, 1, 3, 3, 1, -5, 1, 512, 1, -6, 4, 6, 6, 6, 4, -6, 1, 1024, 1, -7, 8, 8, 6, 6, 8, 8, -7, 1
Offset: 0
Examples
Triangle begins 1, 2, 1, 4, 1, 1, 8, 1, 0, 1, 16, 1, -1, -1, 1, 32, 1, -2, -2, -2, 1, 64, 1, -3, -2, -2, -3, 1
Formula
Number triangle T(n,k)=sum{j=0..n-k, C(j-k,j)C(n-k,j)}
Comments