1, define the variable f 1, start value 1, end value 20, no step default value 1.

2. Define the variable f2, the numerical range is from 1 to 20, and the step size is 2. Print the value of the variable f2.

3. Use the seq function again, with the range of 1 to 20 and the step size of 0.5.

4. Define the variable f4, and use the function seq to assign a value to f4. The length is 2, and the range of values is 10 to 20, namely 10 and 20.

5. Define the variable f5 and use the seq function to assign a value. The length is 20, starting from 2, and the step size is 0.6.

6. Define the variable f6 and use the function seq to assign the value. The parameter is along.with is 10.