<image>Replace the odd numbers with 1 and the even numbers with 0 in Pascal's triangle to get the 0-1 triangle number table as shown in the figure. Counting from the top, the 1st row where all numbers are 1 is the 1st row, the 2nd row where all numbers are 1 is the 3rd row, ..., the nth row where all numbers are 1 is the ___ row.
