ビジービーバー
Σ ( 10 ) > 3 ↑↑↑ 3 = 3 ↑↑ 3 3 3 = 3 3 3 ⋅ ⋅ ⋅ 3 {\displaystyle \Sigma (10)>3\uparrow \uparrow \uparrow 3=3\uparrow \uparrow 3^{3^{3}}=3^{3^{3^{\cdot ^{\cdot ^{\cdot ^{3}}}}}}} (高さは 3 27 = 27 9 = 7 , 625 , 597 , 484 , 987 {\displaystyle 3^{27}={27}^{9}=7,625,597,484,987} )、
先程のΣ(12) は