I took the index in the words, converted the selection to binary, extra 3 zeros, calculated the sha256 digest, took the 1st Element of the hexadecimal to transform it to binary, extra a few zeros to the 8 digits in the binary and received 00000010011 which translates to 19 in https://bookmarkmoz.com/story18892513/the-fact-about-valid-bip39-seed-phrase-that-no-one-is-suggesting