Blogger.com doesn't come with build-in XML sitemaps, but one can use the feeds. That's definitely not a perfect solution, because the feeds list only a few recent posts, but better than nothing.
Here are the standard feed URLS of a blogger blog at blogspot.com (replace "sebastianx" with your subdomain):
http://sebastianx.blogspot.com/feeds/posts/default (ATOM, posts)
http://sebastianx.blogspot.com/feeds/posts/default?alt=rss (RSS, posts)
http://sebastianx.blogspot.com/feeds/comments/default (ATOM, comments)
None of these can be used as a sitemap, because the post-URLs are not located under the sitemap path.
Fortunately, the old feeds still work, although they are served as "text/html" what can confuse things, so I've to stick with
Post it to