I took the index of the words, converted the range to binary, extra three zeros, calculated the sha256 digest, took the main part of the hexadecimal to transform it to binary, additional three zeros on the eight digits of the binary and got 00000010011 which interprets to 19 in decimal. https://worldlistpro.com/story20614130/helping-the-others-realize-the-advantages-of-bip39-mnemonic-phrase-tool