Look at this series: 70, 71, 76, 70, 81, __, 70, 91…

Look at this series: 70, 71, 76, 70, 81, __, 70, 91, ... What number should fill the blank?

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 #29946