Java – How to repeat the same network request (different parameters) multiple times in RxJava/RxAndroid?

So, I have a

/download API that returns a generic Object (based on an index number, which is its own parameter) and then I have to save it to my database, and if the transaction succeeds, I have to increment the index and repeat the same process again, otherwise retry().

I need to repeat about 50 times.

How do I implement this process using Rx-Java?
I’m stuck now. Any help is excellent. Thank you.

Observable.range(1, 50)
    .flatMap(index ->      // for every index make new request
        makeRequest(index) // this shall return Observable<Response>
            .retry(N)      // on error => retry this request N times
    )
    .subscribe(response -> saveToDb(response));

Responses to comments (new requests are made only after the previous response has been saved to the database):

Observable.range(1, 50)
    .flatMap(index ->      // for every index make new request
        makeRequest(index) // this shall return Observable<Response>
            .retry(N)      // on error => retry this request N times
            .map(response -> saveToDb(response)), // save and report success
        1                  // limit concurrency to single request-save
    )
    .subscribe();