I took the index with the words, converted the quantity to binary, extra three zeros, calculated the sha256 digest, took the main Portion of the hexadecimal to transform it to binary, added 3 zeros for the 8 digits of the binary and got 00000010011 which translates to 19 in decimal. https://bookmarksea.com/story18784862/the-ultimate-guide-to-bip39-seed-phrase-github