n queens problem [Clojure]

n-queens.clj

(defn n-queens [n]
        
    (def nList
        (case (mod n 6)
        
            2   (concat
                    (for [i (range 1 (+ (/ n 2) 1))] (* i 2))
                    (concat
                        (list 3 1)
                        (when (> n 6) (for [i (range 4 (+ (/ n 2) 1))] (- (* i 2) 1)))
                        (when (> n 4) (list 5))
                    )
                )
            
            3   (concat
                    (concat
                        (for [i (range 2 (+ (/ n 2) 1))] (* i 2))
                        (list 2)
                    )
                    (concat
                        (for [i (range 3 (+ (/ n 2) 1))] (- (* i 2) 1))
                        (list 1 3)
                    )
                )
            
            (if (even? n)
                (concat
                    (for [i (range 1 (+ (/ n 2) 1))] (* i 2))
                    (for [i (range 1 (+ (/ n 2) 1))] (- (* i 2) 1))
                )
                (concat
                    (for [i (range 1 (/ n 2))] (* i 2))
                    (for [i (range 1 (+ (/ n 2) 1))] (- (* i 2) 1))
                )
            )
            
        )
    )
    
    (for [i (range n)]
        (str (char (+ 97 i)) (nth nList i))
    )
    
)

This is an awful implementation