The dekacthulhum (also called ennacthularxihect) is equal to E100#^^^^^^^^#100 = E100#{8}#100 in Extended Cascading-E Notation.[1] The term was coined by Sbiis Saibian.


The name of this number is based on the words "decation" and "Cthulhu".

Approximations in other notations

Notation Approximation
BEAF \(\{X,X,1,7\}\ \&\ 100\)
Bird's array notation \(\{100,7 [1 [2\neg3] 2] 2\}\)
Hyperfactorial array notation \(100![1] w(1)/6\)
Fast-growing hierarchy \(f_{\varphi(6,0,0)}(99)\)
Hardy hierarchy \(H_{\varphi(6,0,0)}(100)\)
Slow-growing hierarchy \(g_{\vartheta(\Omega_{2}6)}(100)\)


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