I took the index on the words, transformed the quantity to binary, included 3 zeros, calculated the sha256 digest, took the very first part of the hexadecimal to convert it to binary, additional a few zeros to the 8 digits of the binary and got 00000010011 which translates to 19 https://altbookmark.com/story21383542/helping-the-others-realize-the-advantages-of-bip39-seed-phrase-mnemonics-generator