I took the index from the words, transformed the range to binary, added 3 zeros, calculated the sha256 digest, took the first Component of the hexadecimal to transform it to binary, added 3 zeros to the 8 digits of your binary and received 00000010011 which interprets to 19 in decimal. https://ilovebookmark.com/story18921740/not-known-factual-statements-about-bip39-explained