I took the index from the words, transformed the selection to binary, added a few zeros, calculated the sha256 digest, took the 1st Portion of the hexadecimal to convert it to binary, additional 3 zeros on the 8 digits with the binary and received 00000010011 which translates to 19 in https://letsbookmarkit.com/story19570584/the-5-second-trick-for-ledger-seed-phrase-bip39