An explicit rule of a sequence is a function rule where the input is a term's position, and the output is the value of the term. This is opposed to recursive rules, where a term's value is found using previous terms. Explicit rules are often written as where $f(n)$ is the function rule. An example would be the sequence $2,3,4,\dots ,$ which can be described by the explicit rule where $n$ is the position of a term in the sequence. It says that the first term, $a_1,$ has the value $2,$ the second term, $a_2,$ has the value $3,$ and so on.