I took the index with the words, converted the amount to binary, included a few zeros, calculated the sha256 digest, took the first part of the hexadecimal to transform it to binary, additional 3 zeros on the 8 digits of the binary and got 00000010011 which interprets to 19 in https://opensocialfactory.com/story21118934/the-2-minute-rule-for-bip39-all-words