A153159 - OEIS

%I #10 Nov 22 2024 01:46:49

%S 32,243,3125,7776,16807,100000,161051,248832,371293,537824,759375,

%T 1419857,1889568,2476099,3200000,4084101,5153632,6436343,7962624,

%U 11881376,17210368,20511149,24300000,28629151,39135393,45435424

%N a(n) = A007916(n)^5.

%t Select[Range[2,100],GCD@@Last/@FactorInteger@#==1&]^5

%o (Python)

%o from sympy import mobius, integer_nthroot

%o def A153159(n):

%o     def f(x): return int(n+1-sum(mobius(k)*(integer_nthroot(x, k)[0]-1) for k in range(2, x.bit_length())))

%o     m, k = n, f(n)

%o     while m != k: m, k = k, f(k)

%o     return m**5 # _Chai Wah Wu_, Nov 21 2024

%Y Cf. A007916, A153147, A153157, A153158, A153160, A113850.

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Dec 19 2008

%E Edited and extended by _Ray Chandler_, Dec 22 2008