I took the index of the words, transformed the range to binary, included three zeros, calculated the sha256 digest, took the 1st Section of the hexadecimal to transform it to binary, added 3 zeros to your 8 digits of the binary and received 00000010011 which translates to 19 in decimal. http://jaspermuxp089.yousher.com/from-mnemonics-to-security-comprehending-bip39-passphrases-and-their-significance-in-copyright