I took the index with the words, transformed the variety to binary, additional 3 zeros, calculated the sha256 digest, took the first Portion of the hexadecimal to convert it to binary, added 3 zeros for the eight digits in the binary and got 00000010011 which interprets to 19 in decimal. https://doctorbookmark.com/story19657677/the-ultimate-guide-to-bip39-seed-phrase-github