I took the index on the words, converted the variety to binary, extra a few zeros, calculated the sha256 digest, took the first A part of the hexadecimal to convert it to binary, included three zeros for the 8 digits from the binary and got 00000010011 which translates to 19 https://bookmarkingfeed.com/story18882159/getting-my-bip39-words-to-numbers-to-work