I took the index with the words, converted the amount to binary, extra a few zeros, calculated the sha256 digest, took the 1st A part of the hexadecimal to transform it to binary, included three zeros into the 8 digits on the binary and bought 00000010011 which translates to 19 https://socialexpresions.com/story4344194/an-unbiased-view-of-bip39-seed-phrase-github