In the past few months I have seen users in the Google Webmaster Tools Forum asking where they can see their sitemap so they can submit it to Google Webmaster Tools.
The answer is actually really simple. If you visit – domainblogspot.com/robots.txt you should see on that page your sitemap file extension.
You will need the part after the .com to paste into Google Webmaster Tools under sitemaps that looks like –
Hope that works, if you have any questions please go find me on Google+.