Look at this series: 1.25, 7.5, ____, 270, 1620,

Look at this series: 1.25, 7.5, ____, 270, 1620, ... 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 #39006