I took the index of the words, converted the number to binary, included three zeros, calculated the sha256 digest, took the 1st Portion of the hexadecimal to transform it to binary, extra three zeros into the eight digits from the binary and got 00000010011 which interprets to 19 in decimal. https://mysocialguides.com/story4566305/5-essential-elements-for-bip39-explained