I took the index in the words, transformed the range to binary, added 3 zeros, calculated the sha256 digest, took the 1st Element of the hexadecimal to convert it to binary, additional 3 zeros towards the eight digits with the binary and obtained 00000010011 which interprets to 19 in decimal. https://pageoftoday.com/story4254373/not-known-facts-about-bip39-english-words