How many 3-digit positive integers are there, where each digit is positive…

How many 3-digit positive integers are there, where each digit is positive, and no two adjacent digits are same?

This problem repeats another one in the library (at most with different numbers), so it's left out of browsing.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #2023