I took the index in the words, transformed the variety to binary, additional 3 zeros, calculated the sha256 digest, took the main Portion of the hexadecimal to transform it to binary, included three zeros on the 8 digits from the binary and received 00000010011 which translates to 19 in decimal. https://growthbookmarks.com/story18858875/5-simple-techniques-for-bip39-word-list-pdf