How to return the feeds defined my values 'openSearch'?


Hi all! I get feeds - url_my_blog/feeds/posts/default?alt=json. Is it possible to set the value ‘openSearch$startIndex’ and ‘openSearch$itemsPerPage’ to receive entries in the range? For example from 5 to 10. What options are available for this? Can you give any tips or links to materials? Is it possible to do without here JSON API or Blogger API? Thanks )