I took the index on the words, converted the amount to binary, included three zeros, calculated the sha256 digest, took the 1st Element of the hexadecimal to convert it to binary, included 3 zeros for the 8 digits from the binary and received 00000010011 which translates to 19 in decimal. https://bookmarkinglife.com/story4522890/an-unbiased-view-of-bip39-seed-phrase-github