I took the index of your words, transformed the range to binary, extra three zeros, calculated the sha256 digest, took the first part of the hexadecimal to transform it to binary, added three zeros on the eight digits of your binary and received 00000010011 which translates to 19 in decimal. https://bookmarkinglog.com/story18799320/considerations-to-know-about-bip39-seed-phrase-generator