I took the index with the words, transformed the selection to binary, extra 3 zeros, calculated the sha256 digest, took the main A part of the hexadecimal to transform it to binary, added 3 zeros on the eight digits on the binary and bought 00000010011 which interprets to 19 in https://dmozbookmark.com/story18887979/a-review-of-bip39-phrase-list