\nthroot{9}{\nthroot{10}{7^{7}}}

\nthroot{5}{\nthroot{7}{x^{3}}}

\nthroot{3}{\nthroot{6}{3^{9}}}

\nthroot{10}{\nthroot{5}{7^{10}}}

\nthroot{9}{\nthroot{6}{x^{4}}}

\nthroot{8}{\nthroot{6}{7^{2}}}

\nthroot{4}{\nthroot{6}{7^{10}}}

\nthroot{7}{\nthroot{5}{3^{2}}}

\nthroot{9}{\nthroot{10}{3^{5}}}

\nthroot{9}{\nthroot{7}{7^{10}}}

\nthroot{6}{\nthroot{8}{3^{4}}}

\nthroot{7}{\nthroot{7}{3^{7}}}

\nthroot{8}{\nthroot{10}{7^{7}}}

\nthroot{3}{\nthroot{5}{7^{3}}}

\nthroot{3}{\nthroot{3}{x^{2}}}

\nthroot{8}{\nthroot{6}{7^{4}}}

\nthroot{3}{\nthroot{4}{7^{10}}}

\nthroot{3}{\nthroot{10}{7^{6}}}

\nthroot{7}{\nthroot{6}{3^{6}}}

\nthroot{4}{\nthroot{6}{x^{4}}}

\nthroot{5}{\nthroot{7}{7^{8}}}

\nthroot{6}{\nthroot{4}{7^{8}}}

\nthroot{10}{\nthroot{10}{3^{10}}}

\nthroot{10}{\nthroot{3}{3^{3}}}