I took the index in the words, transformed the number to binary, added 3 zeros, calculated the sha256 digest, took the main Portion of the hexadecimal to convert it to binary, extra 3 zeros into the eight digits of your binary and received 00000010011 which translates to 19 in decimal. https://allkindsofsocial.com/story4133523/getting-my-bip39-words-to-numbers-to-work