I took the index from the words, transformed the range to binary, additional 3 zeros, calculated the sha256 digest, took the primary A part of the hexadecimal to convert it to binary, additional three zeros for the eight digits on the binary and obtained 00000010011 which interprets to 19 in https://bookmark-media.com/story19036951/the-fact-about-valid-bip39-seed-phrase-that-no-one-is-suggesting