I took the index of the words, converted the quantity to binary, additional 3 zeros, calculated the sha256 digest, took the 1st part of the hexadecimal to convert it to binary, added three zeros towards the eight digits of your binary and received 00000010011 which interprets to 19 in decimal. https://bouchesocial.com/story20805220/5-simple-techniques-for-bip39-seed-phrase