What does the math term explicit rule mean?

An explicit rule is a mathematical formula that defines a sequence by providing a direct way to calculate any term in the sequence based on its position, often represented as ( a_n = f(n) ), where ( a_n ) is the nth term and ( f(n) ) is a function of n. This contrasts with recursive rules, which define each term based on previous terms. Explicit rules are particularly useful for quickly finding specific terms without needing to compute all preceding terms.