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

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

\nthroot{9}{\nthroot{3}{7^{9}}}

\nthroot{6}{\nthroot{6}{x^{8}}}

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

\nthroot{7}{\nthroot{7}{x^{2}}}

\nthroot{3}{\nthroot{9}{3^{4}}}

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

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

\nthroot{8}{\nthroot{6}{x^{8}}}

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

\sqrt{\nthroot{6}{3^{3}}}

\nthroot{4}{\nthroot{4}{x^{3}}}

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

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

\nthroot{9}{\nthroot{5}{7^{6}}}

\nthroot{8}{\nthroot{3}{7^{4}}}

\nthroot{10}{\nthroot{6}{7^{5}}}

\nthroot{9}{\nthroot{6}{x^{8}}}

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

\nthroot{4}{\nthroot{7}{x^{4}}}

\nthroot{5}{\nthroot{9}{3^{6}}}

\nthroot{4}{\nthroot{7}{3^{5}}}

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