I inserted the missing terminals so that the three key cluster‐producing rules now line up to generate exactly

  1 1 21 14 13 19 17 16 15 1 12 20 18 14 11 5 8 9 4 2 3 1 6 10 7 5 1.

Updated production rules:
rule_310: A19 -> A23 14 A27
rule_326: A23 -> 21 14 13 19 A16 12 20 18
rule_341: A27 -> 11 5 8 9 A14 6 10 7 5 1