I took the index on the words, transformed the quantity to binary, additional three zeros, calculated the sha256 digest, took the initial Element of the hexadecimal to transform it to binary, added three zeros on the 8 digits with the binary and received 00000010011 which translates to 19 in decimal. https://bookmarklinkz.com/story18744486/little-known-facts-about-bip39-words