RxJava implementation of Fibonacci Number

RxFibN.java

public class Main {
  public static void main(String[] args) {
    rxFibN(20).subscribe(new Action1<Integer>() {
      @Override public void call(Integer result) {
        System.out.println(result);
      }
    });
  }

  static Observable<Integer> rxFibN(final int n) {
    return Observable.range(1, n)
        .map(new Func1<Integer, Fib>() {
          @Override public Fib call(Integer integer) {
            return new Fib(0, 1);
          }
        }).reduce(new Func2<Fib, Fib, Fib>() {
      @Override public Fib call(Fib fib, Fib fib2) {
        return new Fib(fib.n2, fib.n1 + fib.n2);
      }
    }).map(new Func1<Fib, Integer>() {
      @Override public Integer call(Fib fib) {
        return fib.n2;
      }
    });
  }

  static class Fib {
    final int n1;
    final int n2;

    Fib(int n1, int n2) {
      this.n1 = n1;
      this.n2 = n2;
    }
  }
}