I took the index of the words, transformed the number to binary, added three zeros, calculated the sha256 digest, took the initial Section of the hexadecimal to convert it to binary, added three zeros towards the 8 digits in the binary and obtained 00000010011 which interprets to 19 in decimal. https://webcastlist.com/story20083652/invalid-bip39-phrase-things-to-know-before-you-buy