I took the index from the words, converted the range to binary, included 3 zeros, calculated the sha256 digest, took the main part of the hexadecimal to convert it to binary, added three zeros towards the 8 digits from the binary and obtained 00000010011 which interprets to 19 in decimal. https://bookmarkboom.com/story18809903/the-invalid-bip39-phrase-diaries