I took the index of your words, transformed the selection to binary, added a few zeros, calculated the sha256 digest, took the first Portion of the hexadecimal to convert it to binary, extra 3 zeros on the eight digits with the binary and obtained 00000010011 which interprets to 19 in https://extrabookmarking.com/story18825240/considerations-to-know-about-bip39-seed-phrase-generator