I took the index of your words, transformed the number to binary, extra three zeros, calculated the sha256 digest, took the main Component of the hexadecimal to transform it to binary, added a few zeros to the 8 digits on the binary and obtained 00000010011 which interprets to 19 in https://greatbookmarking.com/story18855356/a-secret-weapon-for-bip39-words-to-numbers