Sequoia is a program to find frequent sequences with unique occurrences of items and weight averaging. That is, an item may occur only once in each transaction (and thus also in each found frequent subsequence). The subsequences may contain gaps, that is, there may be additional items in the transactions interspersed with the items of the found subsequences. In addition, each item may be associated with a weight in a transaction. In this case, an average weight of each item in a subsequence is computed as the average over the occurrences of the subsequence.