Triangle, read by rows, where T(n,k) = T(n-1,k-1) + T(n-1,k) + T(n-1,k+1) for n>=k>=1, with T(0,0) = 1, T(n,n) = T(n,0) + T(n-1,n-1) for n>=1; T(n,k)=0 when n<k or k<0.

A121400

Triangle, read by rows, where T(n,k) = T(n-1,k-1) + T(n-1,k) + T(n-1,k+1) for n>=k>=1, with T(0,0) = 1, T(n,n) = T(n,0) + T(n-1,n-1) for n>=1; T(n,k)=0 when n<k or k<0.