Let's say you have a vector like so:

(def my-vec [1 2 3 4 5 6])

And you want to extract the first 3 elements and get the remaining elements as a sequence. This can be done as follows:

(let [[x y z & remaining] my-vec]
 (println "first:" x ", second:" y "third:" z "rest:" remaining))
;= first: 1 , second: 2 third: 3 rest: (4 5 6)