I took the index of the words, transformed the variety to binary, added 3 zeros, calculated the sha256 digest, took the first Section of the hexadecimal to convert it to binary, extra three zeros on the 8 digits from the binary and got 00000010011 which interprets to 19 in decimal. https://whitebookmarks.com/story19082512/not-known-factual-statements-about-bip39-explained