I took the index of your words, converted the range to binary, added 3 zeros, calculated the sha256 digest, took the first Section of the hexadecimal to transform it to binary, added 3 zeros into the 8 digits on the binary and acquired 00000010011 which interprets to 19 in decimal. https://telebookmarks.com/story9336543/new-step-by-step-map-for-bip39-english-words