I took the index on the words, converted the range to binary, included 3 zeros, calculated the sha256 digest, took the very first Portion of the hexadecimal to convert it to binary, additional three zeros towards the 8 digits from the binary and bought 00000010011 which interprets to 19 in https://getsocialsource.com/story4264677/the-invalid-bip39-phrase-diaries