I took the index in the words, converted the number to binary, added three zeros, calculated the sha256 digest, took the first part of the hexadecimal to convert it to binary, added three zeros to the 8 digits in the binary and got 00000010011 which translates to 19 in decimal. https://thefairlist.com/story8909698/getting-my-bip39-words-to-numbers-to-work