Is there something preventing you from doing this on your own?
If they have to be, then yes. By last column, do you mean every column needs to be the sum? I thought you mean column n is the sum of all the columns.
It doesn't change anything then because column 2 is the sum of column 1 then; thus, column 1 and 2 are lin. ind.
What do you mean the last column is the sum of previous?
Does that mean the nth column is the sum or does that mean column two is the sum of column 1, column 3 is the sum of column 1 and 2....? If the second is the case, you can make the matrix columns the Fibonacci numbers.
1, 1, 2, 3, 5, 8, ....
*note means a column vector of the nxn matrix
If you make a column vector of all 1s, then = , = , = ,....