This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A153147 #12 Sep 12 2024 07:47:55 %S A153147 8,27,125,216,343,1000,1331,1728,2197,2744,3375,4913,5832,6859,8000, %T A153147 9261,10648,12167,13824,17576,21952,24389,27000,29791,35937,39304, %U A153147 42875,50653,54872,59319,64000,68921,74088,79507,85184,91125,97336,103823 %N A153147 a(n) = A007916(n)^3. %C A153147 2^3=8, 3^3=27, 4^3=64=2^6 is not in the sequence, 5^3=125, 6^3=216, ... %t A153147 Select[Range[2,100],GCD@@Last/@FactorInteger@#==1&]^3 %o A153147 (Python) %o A153147 from sympy import mobius, integer_nthroot %o A153147 def A153147(n): %o A153147 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 A153147 m, k = n, f(n) %o A153147 while m != k: m, k = k, f(k) %o A153147 return m**3 %Y A153147 Cf. A000578, A007916, A153157, A153158, A153159, A153160, A062838. %K A153147 nonn %O A153147 1,1 %A A153147 _Vladimir Joseph Stephan Orlovsky_, Dec 19 2008 %E A153147 Edited by _Ray Chandler_, Dec 22 2008