I took the index of the words, converted the amount to binary, extra a few zeros, calculated the sha256 digest, took the initial A part of the hexadecimal to transform it to binary, added three zeros on the 8 digits with the binary and got 00000010011 which translates to 19 https://bookmarkity.com/story19692368/the-fact-about-bip39-seed-phrase-word-list-that-no-one-is-suggesting