I took the index with the words, transformed the selection to binary, additional 3 zeros, calculated the sha256 digest, took the first Component of the hexadecimal to convert it to binary, additional 3 zeros to the eight digits of your binary and received 00000010011 which translates to 19 in decimal. https://bookmarkplaces.com/story18848236/examine-this-report-on-bip39-mnemonic-phrase-tool