I took the index in the words, converted the selection to binary, included a few zeros, calculated the sha256 digest, took the first A part of the hexadecimal to convert it to binary, added three zeros towards the 8 digits with the binary and bought 00000010011 which translates to 19 https://socialstrategie.com/story4551859/a-secret-weapon-for-bip39-words-to-numbers