I took the index with the words, converted the variety to binary, added three zeros, calculated the sha256 digest, took the 1st A part of the hexadecimal to transform it to binary, included three zeros to your eight digits from the binary and obtained 00000010011 which translates to 19 in https://bookmarkextent.com/story20719336/not-known-factual-statements-about-bip39-explained