I took the index on the words, transformed the variety to binary, extra 3 zeros, calculated the sha256 digest, took the 1st part of the hexadecimal to convert it to binary, additional 3 zeros for the eight digits with the binary and obtained 00000010011 which translates to 19 in decimal. https://maximusbookmarks.com/story19745663/invalid-bip39-phrase-things-to-know-before-you-buy