I took the index in the words, transformed the variety to binary, extra 3 zeros, calculated the sha256 digest, took the initial A part of the hexadecimal to convert it to binary, extra 3 zeros on the eight digits from the binary and obtained 00000010011 which interprets to 19 in https://gatherbookmarks.com/story19639602/facts-about-bip39-seed-phrase-github-revealed