I took the index of your words, converted the variety to binary, extra 3 zeros, calculated the sha256 digest, took the 1st part of the hexadecimal to convert it to binary, added 3 zeros on the 8 digits with the binary and obtained 00000010011 which translates to 19 in decimal. https://cruxbookmarks.com/story19193995/new-step-by-step-map-for-ledger-seed-phrase-bip39