I took the index of your words, converted the range to binary, added 3 zeros, calculated the sha256 digest, took the main Portion of the hexadecimal to transform it to binary, extra 3 zeros to the 8 digits with the binary and got 00000010011 which translates to 19 in decimal. https://bookmarkedblog.com/story20343676/the-ultimate-guide-to-bip39-seed-phrase-github