I took the index from the words, converted the variety to binary, extra a few zeros, calculated the sha256 digest, took the first A part of the hexadecimal to convert it to binary, added three zeros towards the 8 digits from the binary and got 00000010011 which translates to 19 https://bookmarklinking.com/story5171001/an-unbiased-view-of-bip39-seed-phrase-github