The sequence you’ve provided is comprised of the first four square numbers. Let’s break it down:
- The first term is 1 (which is 1 squared, or 12).
- The second term is 4 (which is 2 squared, or 22).
- The third term is 9 (which is 3 squared, or 32).
- The fourth term is 16 (which is 4 squared, or 42).
Following this pattern, it’s clear that the series is simply the squares of the integers in order:
- 12 = 1
- 22 = 4
- 32 = 9
- 42 = 16
- 52 = 25
Hence, the number that should come next in the series is 25.