I took the index of the words, transformed the variety to binary, extra three zeros, calculated the sha256 digest, took the first Section of the hexadecimal to convert it to binary, included 3 zeros into the eight digits of your binary and received 00000010011 which translates to 19 in decimal. https://socialbaskets.com/story4357540/top-guidelines-of-bip39-word-list-pdf