I took the index of the words, converted the amount to binary, additional 3 zeros, calculated the sha256 digest, took the 1st part of the hexadecimal to convert it to binary, additional 3 zeros on the 8 digits with the binary and obtained 00000010011 which interprets to 19 in decimal. https://socialeweb.com/story4192636/5-essential-elements-for-bip39-explained