I took the index on the words, transformed the number to binary, additional a few zeros, calculated the sha256 digest, took the primary part of the hexadecimal to convert it to binary, added 3 zeros into the 8 digits in the binary and got 00000010011 which translates to 19 in https://minibookmarking.com/story19139271/fascination-about-bip39-english-words