I took the index of the words, converted the quantity to binary, added three zeros, calculated the sha256 digest, took the very first A part of the hexadecimal to convert it to binary, added three zeros to the 8 digits from the binary and got 00000010011 which translates to 19 https://nybookmark.com/story20446914/ledger-seed-phrase-bip39-no-further-a-mystery