Recur for every item in doseq

[lugaid vandroiy]

Hi, coderanch users!

I'm at clojure again, and this time I was trying to do something harder, precisely: to solve a parametric variant of the 8 chess queens problem (writing a function that takes board dimensions and pieces with their numbers and returning all of the possible combinations of those).
I read a really large lot of documentation, learnt about the parallelization with pmap, state tracking using atoms, agents, refs, vars, et similia... But there is still one issue that is plagueing me.

(def uniq-configs (agent (list)))
((fn main-loop [board pawns]
                         ;this function calculates
                         ;all of the possible combinations of given pawns.
                         ;;- board should be generated using blank-board
                         ;;- pawns need to be specified in a map (ex: {:rook 1, :queen 2})
                         (let [nxt (get-next-pawn pawns)]
                           (when board
                             (if (not nxt)
                               (if (not (keyword? board)) (send uniq-configs #(cons %2 %1) board))
                               (doseq [sequ (pmap #(let [try (place nxt (first %) (last %) board)]
                                                     (if-not (keyword? try) try))
                                                  (get-free-squares board))]
                                 (recur sequ (update pawns nxt dec)))))))
                      (blank-board 4 4) {:knight 3, :king 1, :bishop 2})

NOTES:

blank-board yields an m X n array of zeroes

get-free-squares returns all of the squares whose value is 0

place yields the board it took in input, but adding a :pawn keyword in the coordinates given in argument and incrementing all of the squares that pawn hits

I need to recur multiple times (read: call the same function for every item in the list), because what I'm trying to do is to analyze every possible combination in order to obtain only the valid ones.
Is such a thing possible in some way? I tried to call banally

 (main-loop sequ (update pawns nxt dec))

but, if I try to call such a function for a larger board (say, 7x7 with 6-8 chess pieces to place around) after ~1min of calculations it eats all the heap, spits out ~1100 results and dies from heap overflow. I tried to give it a larger heap, but it is clearly not a heap issue, but an algorhytmic one.
Recur and trampoline are the only calls that implement TCO in clojure, and I'd like to take advantage from it, in some way.

TL; DR: how do I recur for every item in doseq?

[Sean Corfield]

"Call the same function for each item in a list" sounds like map... Does that help?