I took the index with the words, transformed the selection to binary, included three zeros, calculated the sha256 digest, took the first Portion of the hexadecimal to convert it to binary, included three zeros towards the 8 digits in the binary and received 00000010011 which translates to 19 in decimal. https://mysitesname.com/story8551284/facts-about-bip39-seed-phrase-github-revealed