I took the index on the words, converted the number to binary, extra 3 zeros, calculated the sha256 digest, took the very first Element of the hexadecimal to transform it to binary, added three zeros to the 8 digits on the binary and got 00000010011 which translates to 19 in https://checkbookmarks.com/story4345077/not-known-facts-about-bip39-english-words