I took the index with the words, transformed the range to binary, additional three zeros, calculated the sha256 digest, took the primary Element of the hexadecimal to convert it to binary, additional 3 zeros on the 8 digits in the binary and obtained 00000010011 which interprets to 19 in decimal. https://bookmarkspedia.com/story4367862/facts-about-bip39-seed-phrase-github-revealed