I took the index with the words, transformed the range to binary, included 3 zeros, calculated the sha256 digest, took the primary part of the hexadecimal to convert it to binary, added 3 zeros on the 8 digits on the binary and acquired 00000010011 which interprets to 19 in decimal. https://livebookmarking.com/story19005098/bip39-phrase-generator-can-be-fun-for-anyone