I took the index of your words, converted the range to binary, included three zeros, calculated the sha256 digest, took the very first Component of the hexadecimal to convert it to binary, added a few zeros for the eight digits on the binary and acquired 00000010011 which translates to 19 https://alphabookmarking.com/story18843100/ledger-seed-phrase-bip39-no-further-a-mystery