I took the index in the words, converted the range to binary, additional a few zeros, calculated the sha256 digest, took the initial Element of the hexadecimal to transform it to binary, added three zeros for the eight digits of the binary and bought 00000010011 which translates to 19 in https://bookmarkworm.com/story18948162/the-5-second-trick-for-ledger-seed-phrase-bip39