Recursive scala implementation of Towers of Hanoi

TowersOfHanoi.scala

import scala.collection.immutable._

object TowersOfHanoi extends App {

        case class State(a : Seq[Int], b: Seq[Int], c: Seq[Int])
        val discs = 8

        val state = State(0 to discs, List[Int](), List[Int]());

        def moveTower(disc: Int, state: State) : State = {
                val newState = if (disc == 0) {
                        State(state.a.tail, 0 +: state.b, state.c)
                } else {
                        val i1 = moveTower(disc - 1, State(state.a, state.c, state.b))
                        val i2 = State(i1.a.tail, disc +: i1.c, i1.b)
                        val i3 = moveTower(disc - 1, State(i2.c, i2.b, i2.a))
                        State(i3.c, i3.b, i3.a)
                }
                newState
        }

        println(moveTower(discs, state))
}