I took the index of the words, converted the number to binary, additional a few zeros, calculated the sha256 digest, took the very first part of the hexadecimal to transform it to binary, included three zeros for the eight digits on the binary and got 00000010011 which interprets to 19 https://yoursocialpeople.com/story4206174/facts-about-bip39-seed-phrase-word-list-revealed