I put online a site 1 week ago. In first days I got indexed about 300 pages. But next day it was only 112. Today morning I tried again on google site:mywebsite.com and it showed 343. Now I just tried and it is again only 126. Why is google removing pages after it just indexed?
Yes what malcolm1 said different data centers. In the meantime I would go over each Title and Description and make sure they are unique, even changing just one word is OK. This will help to keep them out of the omitted results. You want nice and healthy indexed pages once all data centeres have updated.
I thing its due to multiple data centers.. Accordingly the updation indexed pages or ranking may vary, but at last after finish the updatipon may get some stabled ranking