I took the index on the words, converted the variety to binary, additional a few zeros, calculated the sha256 digest, took the initial Element of the hexadecimal to convert it to binary, included 3 zeros into the 8 digits with the binary and obtained 00000010011 which interprets to 19 in https://bookmarkrange.com/story20476117/ledger-seed-phrase-bip39-no-further-a-mystery