I took the index of your words, transformed the quantity to binary, extra three zeros, calculated the sha256 digest, took the first part of the hexadecimal to convert it to binary, included three zeros on the eight digits from the binary and obtained 00000010011 which translates to 19 in decimal. https://bookmarkfavors.com/story4590797/new-step-by-step-map-for-ledger-seed-phrase-bip39