I took the index of your words, converted the quantity to binary, added 3 zeros, calculated the sha256 digest, took the first part of the hexadecimal to transform it to binary, additional 3 zeros towards the eight digits in the binary and got 00000010011 which interprets to 19 in decimal. https://bookmarking1.com/story18840075/5-essential-elements-for-bip39-explained