I took the index in the words, transformed the number to binary, added 3 zeros, calculated the sha256 digest, took the main Portion of the hexadecimal to convert it to binary, included three zeros towards the eight digits of the binary and acquired 00000010011 which interprets to 19 in decimal. https://free-bookmarking.com/story19091138/bip39-seed-phrase-mnemonics-generator-an-overview