Quadrommthet

Quadrommthet is equal to \(f_{\theta(\Omega_4)}(10)\) using the fast-growing hierarchy and Feferman's \(\theta\)-function with this system of fundamental sequences. Also it is equal to \( f_{\psi_0(\psi_4^3(0))}(10)\) using the fast-growing hierarchy with fundamental sequences using equalities to outputs of Buchholz's function.My system of number names (FGS) - Traveling To The Infinity The term was coined by wiki user Denis Maksudov.
== Etymology ==
The 3 parts of the name, "quadri", "omm" and "thet", mean 4, \(\Omega\)-ordinals and \(\theta\) function respectively, which form \(\theta(\Omega_4)\) when concatenated backwards. So the full name indicates the ordinal index of the FGH.
== Approximations ==
Notation 	Approximation
Bird's array notation 	\(\{10,10 [1 [1 [1 [1 [1 \backslash_4 2 \backslash_5 2] 2] 2] 2] 2] 2\}\)
Hardy hierarchy (using Buchholz hierarchy 	\(H_{\psi_0(\psi_4^3(0))}(10)\)
Slow-growing hierarchy (using Buchholz hierarchy)	\(g_{\psi_0(\Omega_4^{\Omega_4})}(10)\)
== Sources ==
Category:Numbers
Category:Numbers by Denis Maksudov
Category:10-based FGH numbers
Category:Higher computable level