I took the index with the words, transformed the range to binary, included a few zeros, calculated the sha256 digest, took the main Section of the hexadecimal to convert it to binary, additional three zeros towards the 8 digits from the binary and received 00000010011 which translates to 19 in https://hypebookmarking.com/story19389164/the-2-minute-rule-for-bip39-all-words