I took the index from the words, converted the number to binary, included three zeros, calculated the sha256 digest, took the main A part of the hexadecimal to convert it to binary, additional three zeros towards the 8 digits from the binary and received 00000010011 which translates to 19 in https://ilovebookmark.com/story19038413/ledger-seed-phrase-bip39-no-further-a-mystery