# A lower triangular matrix with implicit 1.0's on the diagonal
# 1 0 0 0
# 2 1 0 0 
# 3 2 1 0
# 4 3 2 1
#
4 4 6
1 0 2
2 0 3
2 1 2
3 0 4
3 1 3
3 2 2
