I took the index of your words, transformed the quantity to binary, included a few zeros, calculated the sha256 digest, took the 1st Element of the hexadecimal to transform it to binary, included a few zeros to your 8 digits in the binary and got 00000010011 which interprets to 19 https://bookmarkspedia.com/story4395132/a-secret-weapon-for-bip39-words-to-numbers