The NumberSequence op is useful when you need to define the flow of a value (the order in which ops gets updated about the new value). Think about a Sequence op for values here.
First the left value out port is executed (sets the variable "myValue"), then the second one (sets the variable "anotherVariable"), …, at the end the trigger port triggers.

This is a very special op and you will probably need it rarely, only when from one outgoing value multiple should happen in a certain order.