Talk:2018 AIME II Problems/Problem 15
The provided solution appears to be incorrect. It does not appear to take into account the possibility that e.g., is -2 or -3.
I believe the correct answer is 267. There is a relatively simple dynamic programming solution for this (which I'm happy to provide), but we can also confirm with the following Python script:
deltas = [-3,-2,-1,1,2,3] count = 0 for d1 in deltas: for d2 in deltas: for d3 in deltas: for d4 in deltas: for d5 in deltas: for d6 in deltas: if d1 + d2 + d3 + d4 + d5 + d6 == 12: count += 1 print count