I took the index in the words, converted the quantity to binary, added a few zeros, calculated the sha256 digest, took the very first Section of the hexadecimal to convert it to binary, included three zeros to your eight digits in the binary and received 00000010011 which translates to 19 https://bookmarkmiracle.com/story20337692/a-secret-weapon-for-bip39-words-to-numbers