I took the index from the words, converted the amount to binary, included 3 zeros, calculated the sha256 digest, took the primary Element of the hexadecimal to transform it to binary, additional three zeros for the 8 digits on the binary and got 00000010011 which interprets to 19 in decimal. https://altbookmark.com/story20480164/ledger-seed-phrase-bip39-no-further-a-mystery