Seed Hex

seeeed

If you mean you want to know blockchain.info generate wallet, you probably want to visit their GitHub page on https://github.com/blockchain. The repository you're probably looking for is https://github.com/blockchain/My-Wallet-V3.

How did you get this dump? Did you happen to run any commands in the browser console or download the wallet.aes file (I don't remember if that's the name) from blockchain.info(.com)? I remember that I could only export the private keys from the browser console, but not something like seedhex. But why are you curious about it? Apparently it should follow the same BIP39 standard for generating wallets, through the initial entropy generated by the BIP39 words.