I took the index with the words, converted the variety to binary, added three zeros, calculated the sha256 digest, took the main Section of the hexadecimal to transform it to binary, extra 3 zeros into the eight digits of your binary and obtained 00000010011 which interprets to 19 in decimal. https://opensocialfactory.com/story19279083/considerations-to-know-about-bip39-word-list-pdf