I took the index on the words, converted the range to binary, included three zeros, calculated the sha256 digest, took the 1st A part of the hexadecimal to transform it to binary, extra a few zeros towards the 8 digits of the binary and got 00000010011 which translates to 19 https://bookmarkforce.com/story19076939/top-guidelines-of-bip39-word-list-pdf