I took the index in the words, transformed the variety to binary, added 3 zeros, calculated the sha256 digest, took the main Component of the hexadecimal to convert it to binary, additional a few zeros towards the eight digits with the binary and got 00000010011 which translates to 19 in https://bookmarkbirth.com/story18903424/ledger-seed-phrase-bip39-no-further-a-mystery