I took the index with the words, transformed the number to binary, extra three zeros, calculated the sha256 digest, took the first Portion of the hexadecimal to convert it to binary, included three zeros for the 8 digits from the binary and obtained 00000010011 which translates to 19 in decimal. https://socialmediaentry.com/story4199498/how-much-you-need-to-expect-you-ll-pay-for-a-good-bip39-definition