Power Tower
where
is Knuth's (1976) Arrow Notation.
The infinite power tower
converges Iff 
(
).See also Ackermann Function, Fermat Number, Mills' Constant
References
Knuth, D. E. ``Mathematics and Computer Science: Coping with Finiteness. Advances in our Ability to Compute are Bringing us Substantially Closer to Ultimate Limitations.'' Science 194 1235-1242, 1976. Vardi, I. Computational Recreations in Mathematica. Reading, MA: Addison-Wesley, pp. 11 and 226-229, 1991.
- Pentagonal Gyrocupolarotunda
- Pentagonal Hexecontahedron
- Pentagonal Icositetrahedron
- Pentagonal Number
- Pentagonal Orthobicupola
- Pentagonal Orthobirotunda
- Pentagonal Orthocupolarontunda
- Pentagonal Prism
- Pentagonal Pyramid
- Pentagonal Pyramidal Number
- Pentagonal Rotunda
- Pentagonal Tiling
- Pentagram
- Pentagrammic Antiprism
- Pentagrammic Concave Deltahedron
- Pentagrammic Crossed Antiprism
- Pentagrammic Deltahedron
- Pentagrammic Dipyramid
- Pentagrammic Prism
- Pentakaidecagon
- Pentakis Dodecahedron
- Pentalpha
- Pentangle
- Pentatope
- Pentatope Number