I took the index with the words, transformed the number to binary, added three zeros, calculated the sha256 digest, took the initial Portion of the hexadecimal to convert it to binary, additional three zeros towards the eight digits from the binary and received 00000010011 which translates to 19 in decimal. https://bookmarkfavors.com/story4348407/facts-about-bip39-seed-phrase-github-revealed