I took the index from the words, transformed the selection to binary, extra a few zeros, calculated the sha256 digest, took the 1st Element of the hexadecimal to convert it to binary, added three zeros to the 8 digits from the binary and received 00000010011 which translates to 19 in https://thesocialvibes.com/story4305255/little-known-facts-about-bip39-seed-phrase-list