I took the index with the words, transformed the number to binary, included a few zeros, calculated the sha256 digest, took the very first Component of the hexadecimal to transform it to binary, additional 3 zeros towards the eight digits with the binary and bought 00000010011 which interprets to 19 https://bookmarkja.com/story20842179/not-known-factual-statements-about-bip39-explained