I took the index of your words, transformed the range to binary, added three zeros, calculated the sha256 digest, took the initial Component of the hexadecimal to convert it to binary, additional 3 zeros on the eight digits from the binary and bought 00000010011 which translates to 19 in decimal. https://bookmarkproduct.com/story18939187/little-known-facts-about-bip39-seed-phrase-list