I took the index with the words, transformed the amount to binary, included a few zeros, calculated the sha256 digest, took the 1st Portion of the hexadecimal to transform it to binary, additional 3 zeros into the 8 digits of the binary and obtained 00000010011 which translates to 19 in https://ilovebookmark.com/story18744373/how-much-you-need-to-expect-you-ll-pay-for-a-good-bip39-definition