I took the index from the words, converted the range to binary, added three zeros, calculated the sha256 digest, took the first Section of the hexadecimal to transform it to binary, included 3 zeros for the 8 digits in the binary and got 00000010011 which interprets to 19 in decimal. https://bookmark-vip.com/story18920506/considerations-to-know-about-bip39-word-list-pdf