I took the index in the words, transformed the range to binary, included three zeros, calculated the sha256 digest, took the 1st A part of the hexadecimal to transform it to binary, additional three zeros into the eight digits on the binary and obtained 00000010011 which interprets to 19 in https://natural-bookmark.com/story18815533/invalid-bip39-phrase-things-to-know-before-you-buy