I took the index in the words, transformed the range to binary, included 3 zeros, calculated the sha256 digest, took the first Component of the hexadecimal to convert it to binary, additional 3 zeros to your eight digits of the binary and acquired 00000010011 which translates to 19 in decimal. https://myfirstbookmark.com/story18858032/how-much-you-need-to-expect-you-ll-pay-for-a-good-bip39-seed-phrase-mnemonics-generator