I took the index of your words, converted the selection to binary, added 3 zeros, calculated the sha256 digest, took the initial Section of the hexadecimal to convert it to binary, included 3 zeros for the 8 digits of the binary and obtained 00000010011 which interprets to 19 in decimal. https://thesocialvibes.com/story4478455/facts-about-bip39-seed-phrase-word-list-revealed