I took the index of your words, converted the amount to binary, included 3 zeros, calculated the sha256 digest, took the first A part of the hexadecimal to convert it to binary, additional 3 zeros for the 8 digits with the binary and acquired 00000010011 which interprets to 19 in https://thesocialcircles.com/story4459561/the-greatest-guide-to-seed-phrase-bip39