Pentacthulootethrinoogol

is equal to \(\{100,100[1[1\backslash2\neg2]1[1[1\backslash2]2\neg2]2]2\}\) in Bird's array notation, using the modified Hierarchical Hyper-Nested Array Notation. The term was coined by googology user .
==Approximations==
Notation 	Approximation
Bowers' Exploding Array Function (intended) 	\(\{X,X,X \uparrow\uparrow X,2\} \& 100\) (weak bound, non-climbing)
\(X \uparrow\uparrow\uparrow X \uparrow\uparrow X \& 100\) (strong bound, climbing)
Extended Cascading-E Notation 	\(\text{E}100\#\text{^^^}\#\text{^^}\#99\)
DeepLineMadom's Array Notation 	\(100[1\{1<1/2>1<1\{1/2\}2>2\}2]100\)
Strong array notation (intended) 	\(\text{s}(100,100\{1\{1`2^{`}\}1\{1\{1`2\}2^{`}\}2\}2)\)
Username5243's Array Notation (intended) 	\(100[0\{0\{0,_1 1\}_1 0\{0\{0,_1 1\}1\}_1 1\}1]100\)
Fast-growing hierarchy (with this system of fundamental sequences)	\(f_{\varphi(1,\varepsilon_0,0)}(100)\)
Hardy hierarchy (with this system of fundamental sequences) 	\(H_{\varphi(1,\varepsilon_0,0)}(100)\)
Slow-growing hierarchy (with this system of fundamental sequences)	\(g_{\psi_0(\Omega_2^{\Omega_2+\varepsilon_0})}(100)\)
==Sources==
Category:Numbers
Category:Numbers by HaydenTheGoogologist2009
Category:Bachmann's collapsing level
Category:Bird's array notation numbers