I took the index with the words, converted the quantity to binary, additional 3 zeros, calculated the sha256 digest, took the main part of the hexadecimal to convert it to binary, additional three zeros for the 8 digits from the binary and received 00000010011 which translates to 19 in decimal. https://mylittlebookmark.com/story4462261/top-guidelines-of-bip39-word-list-pdf