I took the index on the words, converted the range to binary, added three zeros, calculated the sha256 digest, took the main part of the hexadecimal to transform it to binary, included three zeros for the eight digits of the binary and received 00000010011 which translates to 19 in decimal. https://socialmarkz.com/story9267321/helping-the-others-realize-the-advantages-of-bip39-seed-phrase-mnemonics-generator