I took the index with the words, transformed the number to binary, additional three zeros, calculated the sha256 digest, took the primary part of the hexadecimal to transform it to binary, added three zeros for the eight digits in the binary and bought 00000010011 which interprets to 19 in decimal. https://mysocialname.com/story4081623/ledger-seed-phrase-bip39-no-further-a-mystery