Googology Wiki
Googology Wiki

The pentacthulteron is equal to E100#^^^####100 in Extended Cascading-E Notation.[1] The term was coined by Sbiis Saibian.


The name of this number is based on the number pentacthulhum and the word "teron" from "polyteron".

Approximations in other notations

Notation Approximation
BEAF \(\{X,X,4,2\}\ \&\ 100\)
Bird's array notation \(\{100,100[1[1 \neg 3]1 \backslash 1 \backslash 1 \backslash 2]2\}\)
Hyperfactorial array notation \(100![1(1)1,1,1,1,2,2]\)
Fast-growing hierarchy (with this system of fundamental sequences) \(f_{\varphi(1,3,0)}(99)\)
Hardy hierarchy \(H_{\varphi(1,3,0)}(100)\)
Slow-growing hierarchy \(g_{\vartheta(\Omega_2+\vartheta_1(\Omega_2+3))}(100)\)


  1. Saibian, Sbiis. 4.3.4 - Forging Extended Cascading-E Numbers Part II. Retrieved May 30, 2014.