I took the index from the words, converted the range to binary, added a few zeros, calculated the sha256 digest, took the initial Portion of the hexadecimal to convert it to binary, extra a few zeros for the 8 digits on the binary and obtained 00000010011 which interprets to 19 https://socialimarketing.com/story5024696/the-fact-about-valid-bip39-seed-phrase-that-no-one-is-suggesting