I took the index on the words, transformed the quantity to binary, added three zeros, calculated the sha256 digest, took the initial Portion of the hexadecimal to transform it to binary, extra three zeros to the eight digits with the binary and acquired 00000010011 which interprets to 19 in decimal. https://travialist.com/story9018882/invalid-bip39-phrase-things-to-know-before-you-buy