get 8 digit unique value when sequence of 7 positive integers given as input

Question

Consider a random sequence of numbers, like 1, 4, 15, 21, 27, 15... There are no constraints on what numbers may appear in the sequence and the sequence consist of 7 positive integers and each integer range from 0 to 255.The question is, do we have a function that will give unique output by performing mathematical operations on this sequence? By unique, I mean when the function is applied on sequence A, it must output a value that's different from the output obtained by applying the same function on any other sequence (or the same sequence but numbers placed in different order) in the world.and i need the output in 8 digits only.thanks

Answer 1

Hint: ${}{}{}{}$

$$256^7 > 10^8$$