I took the index in the words, converted the range to binary, extra three zeros, calculated the sha256 digest, took the primary part of the hexadecimal to transform it to binary, additional 3 zeros to the 8 digits in the binary and received 00000010011 which interprets to 19 in decimal. https://wisesocialsmedia.com/story4447514/5-simple-techniques-for-bip39-word-list-pdf