I took the index in the words, converted the range to binary, added three zeros, calculated the sha256 digest, took the very first Portion of the hexadecimal to convert it to binary, additional three zeros towards the 8 digits in the binary and obtained 00000010011 which translates to 19 in https://bookmarks-hit.com/story19855800/facts-about-bip39-seed-phrase-github-revealed