Is there any way to create Executor that will have always at least 5 threads, and maximum of 20 threads, and unbounded queue for tasks (meaning no task is rejected)

I tried new ThreadPoolExecutor(5, 20, 60L, TimeUnit.SECONDS, queue) with all possibilities that I thought of for queue:

new LinkedBlockingQueue() // never runs more than 5 threads
new LinkedBlockingQueue(1000000) // runs more than 5 threads, only when there is more than 1000000 tasks waiting
new ArrayBlockingQueue(1000000) // runs more than 5 threads, only when there is more than 1000000 tasks waiting
new SynchronousQueue() // no tasks can wait, after 20, they are rejected

and none worked as wanted.