I took the index from the words, transformed the variety to binary, included three zeros, calculated the sha256 digest, took the first Component of the hexadecimal to convert it to binary, extra 3 zeros to your eight digits of your binary and bought 00000010011 which interprets to 19 in decimal. https://bookmarksfocus.com/story4352579/little-known-facts-about-bip39-seed-phrase-list