I took the index of the words, transformed the selection to binary, included 3 zeros, calculated the sha256 digest, took the 1st Element of the hexadecimal to transform it to binary, extra 3 zeros to your eight digits on the binary and acquired 00000010011 which translates to 19 in decimal. https://socialbookmarkgs.com/story18853669/5-essential-elements-for-bip39-explained