Puzzle ZQSE 

Workings

Hint
This question involves the months of the year in some way.

Answer
4 3 1.

Reasoning
This is the sequence of the length of the name of the month and the number of days in that month.

For example, January has 7 letters and 31 days: 7 3 1.

February has 8 letters and 28 days, etc.

The next 3 digits are therefore 431 since July has 4 letters and 31 days.