The tethragodentol (also called tethrathoth-ad-godoctolium) is equal to E100(#^^#)^(#^^#)9 using Extended Cascading-E Notation.[1] The term was coined by Sbiis Saibian.


The name of this number is based on the number "tethrathoth" and the number "godoctol".

Approximations in other notations

Notation Approximation
BEAF \(\{100,100(X \uparrow\uparrow X*X^{X^{X^{X^{X^{X^{X^{X^X}}}}}}}) 2\}\)[2]
Bird's array notation \(\{100,100 [1[1[1[1[1]2]2]2]2 \backslash 2] 2\}\)
Fast-growing hierarchy \(f_{\varepsilon_0^{\omega\uparrow\uparrow9}}(100)\)
Hardy hierarchy \(H_{\varepsilon_0^{\omega\uparrow\uparrow9}}(100)\)
Slow-growing hierarchy \(g_{\vartheta(\varepsilon_{\Omega 2}^{\Omega^{\Omega^{\Omega^{\Omega^{\Omega^{\Omega^{\Omega^{\Omega^\omega}}}}}}}})}(100)\)


  1. Saibian, Sbiis. 4.3.7 Extended Cascading-E Numbers Part IOne to Infinity. Retrieved 2017-01-02.
  2. Using particular notation \(\{a,b (A) 2\} = A \&\ a\) with prime b.
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