I took the index on the words, converted the range to binary, added three zeros, calculated the sha256 digest, took the primary A part of the hexadecimal to convert it to binary, additional a few zeros to the 8 digits of your binary and received 00000010011 which interprets to 19 https://myeasybookmarks.com/story4496481/facts-about-bip39-seed-phrase-word-list-revealed