Use Count

– You can specify the order and number of times to repeat each object with the list view that appears after checking this option box.

– Plus and Minus add and remove a selected object.

– Up and Down arrows change the order of the emitted objects.

– Count box is used to set the number of repetitions of the selected object.

– Here you can see the settings of Example 4 (video on the right):

Blender Particles Collection Use Count