I took the index of the words, converted the range to binary, added 3 zeros, calculated the sha256 digest, took the primary part of the hexadecimal to convert it to binary, included three zeros for the eight digits on the binary and got 00000010011 which translates to 19 in decimal. https://gorillasocialwork.com/story20471319/the-ultimate-guide-to-bip39-seed-phrase-github