I took the index of the words, transformed the quantity to binary, additional 3 zeros, calculated the sha256 digest, took the first Section of the hexadecimal to transform it to binary, additional 3 zeros to the eight digits from the binary and received 00000010011 which translates to 19 in decimal. https://businessbookmark.com/story4222481/considerations-to-know-about-bip39-word-list-pdf