I took the index on the words, converted the range to binary, added 3 zeros, calculated the sha256 digest, took the 1st Portion of the hexadecimal to transform it to binary, extra three zeros for the 8 digits in the binary and obtained 00000010011 which interprets to 19 in decimal. https://bookmarkmargin.com/story18852378/the-fact-about-bip39-seed-phrase-word-list-that-no-one-is-suggesting