This sequence puzzle gives the letters: J F M A M J J A and asks what comes next.
The answer is S.
Each letter is the first letter of a month in order: January, February, March, April, May, June, July, and August.
The next month is September, so the next letter must be S.
This is not a mathematical sequence. The clue is hidden in a familiar list that most people know by heart. Once you recognize that the letters match the months of the year, the pattern becomes straightforward.
The sequence would continue with O for October, N for November, and D for December.


