I took the index with the words, transformed the selection to binary, added 3 zeros, calculated the sha256 digest, took the very first Section of the hexadecimal to convert it to binary, included 3 zeros for the 8 digits of your binary and acquired 00000010011 which interprets to 19 in https://socialtechnet.com/story4252714/how-much-you-need-to-expect-you-ll-pay-for-a-good-bip39-seed-phrase-mnemonics-generator