I took the index of your words, transformed the number to binary, additional three zeros, calculated the sha256 digest, took the initial Section of the hexadecimal to convert it to binary, additional 3 zeros to your eight digits with the binary and obtained 00000010011 which translates to 19 in decimal. https://leftbookmarks.com/story19210349/bip39-phrase-generator-can-be-fun-for-anyone