User blog comment:Flavio61/Louis Epstein number list/@comment-27173506-20160118190252/@comment-12.144.5.30-20160208223355

3 u 4 is not about equal to 3^^4.

3^^4=3^3^3^3=3^3^27=3^7625597484987=3 u 2.

3 u 4=3^(3^(27^(3^7625597484987)^(3^(3^(27^(3^7625597484987)))))