I took the index on 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 in the binary and received 00000010011 which translates to 19 in decimal. https://nowbookmarks.com/story18831146/the-fact-about-valid-bip39-seed-phrase-that-no-one-is-suggesting