I took the index with the words, converted the amount to binary, added 3 zeros, calculated the sha256 digest, took the primary Portion of the hexadecimal to convert it to binary, included three zeros to your eight digits on the binary and got 00000010011 which translates to 19 in decimal. https://iwanttobookmark.com/story18915151/examine-this-report-on-bip39-mnemonic-phrase-tool