S(sub)5 in { 10, 30, 90, 270, 810, 2430} what is the answer

The answer depends on the value of S(sub)5. If S(sub)5 refers to the 5th term of a sequence, then the answer will depend on the rule or pattern followed by the sequence. Without knowing the rule, it is impossible to determine the answer.

If S(sub)5 represents a specific value or variable unrelated to a sequence, then the answer would need to be provided.