It's fairly trivial to scrape the list of followers (instagram's website's API returns these in batches that include an end_cursor, and use the end_cursor to get the next batch.
However I'd like to be able to get just a slice of a follower list, eg followers 2000-3000 (where a user has for example 5000 total) without first retrieving followers numbered 0-1999.
The end_cursor value is a base64 string which decodes to an 88 character string which seems to usually begin with 'AQ'.
Beyond this I'm stumped what the value is or what they are doing to obscure it, but figuring it out would be helpful for my purposes of reading my followers from the API.
This section of the API is now completely deprecated and nonfuctional.
For what it's worth, I had played with it a bit and it most likely had a session nonce somehow encoded.