I took the index in the words, converted the number to binary, additional three zeros, calculated the sha256 digest, took the 1st part of the hexadecimal to convert it to binary, added three zeros towards the 8 digits from the binary and received 00000010011 which translates to 19 in decimal. https://bookmarkdistrict.com/story18665154/little-known-facts-about-bip39-seed-phrase-list