I took the index with the words, transformed the range to binary, included a few zeros, calculated the sha256 digest, took the main part of the hexadecimal to transform it to binary, added three zeros towards the 8 digits with the binary and obtained 00000010011 which interprets to 19 in https://totalbookmarking.com/story18842488/facts-about-bip39-seed-phrase-word-list-revealed