User blog comment:Nayuta Ito/PEGG detailed log/@comment-30754445-20171030122616

Just a side note:

5 arrows is not "pentation". There's a offset of 2 with the names:

2 arrows = tetration

3 arrows = pentation

4 arrows = hexation

etc.

So borrowing from geological terminology, you can say that we're at the start of the "heptation period" of the "J era".