I took the index with the words, transformed the range to binary, extra a few zeros, calculated the sha256 digest, took the first A part of the hexadecimal to transform it to binary, additional 3 zeros for the 8 digits with the binary and obtained 00000010011 which interprets to 19 https://tripsbookmarks.com/story18951770/a-secret-weapon-for-bip39-words-to-numbers