This simple addition series adds 4 to each number to arrive at the next.

In this simple addition with repetition series, each number in the series repeats itself, and then increases by 12 to arrive at the next number.

This is a simple subtraction series, in which 4 is subtracted from each number to arrive at the next.

This is a simple subtraction series, in which 3 is subtracted from each number to arrive at the next.

This is an alternating addition series with repetition, in which a random number, 66, is interpolated as every third number. The regular series adds 2, then 3, then 2, and so on, with 66 repeated after each "add 2" step.

This is an alternating repetition series. The number 32 alternates with a series in which each number decreases by 2.

Here, there are two alternating patterns, one addition and one subtraction. The first starts with 2 and increases by 2; the second starts with 44 and decreases by 3.

Two patterns alternate here, with every third number following the alternate pattern. In the main series, beginning with 4, 3 is added to each number to arrive at the next. In the alternating series, beginning with 26, 6 is subtracted from each number to arrive at the next.

Here, every third number follows a different pattern from the main series. In the main series, beginning with 16, 10 is added to each number to arrive at the next. In the alternating series, beginning with 56, 12 is added to each number to arrive at the next.

In this simple subtraction series, the numbers decrease by 3.