I took the index with the words, converted the variety to binary, extra a few zeros, calculated the sha256 digest, took the main part of the hexadecimal to transform it to binary, extra 3 zeros on the 8 digits on the binary and obtained 00000010011 which interprets to 19 in https://bookmarkize.com/story18930290/an-unbiased-view-of-bip39-seed-phrase-github