I took the index of the words, transformed the range to binary, included 3 zeros, calculated the sha256 digest, took the first part of the hexadecimal to convert it to binary, added 3 zeros into the eight digits with the binary and got 00000010011 which translates to 19 in decimal. https://socials360.com/story9147750/considerations-to-know-about-bip39-word-list-pdf