I took the index with the words, converted the range to binary, additional 3 zeros, calculated the sha256 digest, took the main Portion of the hexadecimal to transform it to binary, included three zeros to your 8 digits in the binary and obtained 00000010011 which translates to 19 in decimal. http://josueaqpi312.huicopper.com/from-words-to-riches-just-how-to-successfully-make-use-of-bip39-passphrases-for-your-copyright-budgets