I took the index of your words, transformed the selection to binary, added 3 zeros, calculated the sha256 digest, took the 1st Portion of the hexadecimal to transform it to binary, extra 3 zeros into the eight digits with the binary and acquired 00000010011 which interprets to 19 in decimal. https://nimmansocial.com/story8743084/helping-the-others-realize-the-advantages-of-bip39-mnemonic-phrase-tool