I took the index on the words, transformed the quantity to binary, additional three zeros, calculated the sha256 digest, took the primary Component of the hexadecimal to convert it to binary, included 3 zeros into the 8 digits of your binary and got 00000010011 which translates to 19 in decimal. https://seobookmarkpro.com/story18824779/ledger-seed-phrase-bip39-no-further-a-mystery