What is common difference of the following arithmetic sequence?

To find the common difference of an arithmetic sequence, subtract any term from the next term.

For example, if you ave the arithmetic sequence 1, 5, 9, 13, 17, ..., to find the common difference, you can subtract 9 - 5 to get 4. The common difference is 4. Subtracting any term from the next term will give you the same answer.

To follow the common difference, you just subtract each number from the number following it in the sequence.