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 A279984 #22 Oct 13 2024 11:16:43
%S A279984 1,2,3,5,7,9,12,14,18,22,24,28,32,34,38,43,49,51,56,60,62,68,71,77,85,
%T A279984 88,90,94,96,100,112,115,121,123,132,134,140,146,150,155,161,163,173,
%U A279984 175,178,180,192,203,206,208,212,218,220,229,234,240,246,248,254
%N A279984 Positions of the prime numbers in the sequence of numbers that are not perfect powers (A007916).
%H A279984 Hugo Pfoertner, <a href="/A279984/b279984.txt">Table of n, a(n) for n = 1..10000</a>
%F A279984 A007916(a(n)) = A000040(n).
%t A279984 nn=100;rads=Select[Range[2,nn],GCD@@FactorInteger[#][[All,2]]===1&];
%t A279984 Table[Position[rads,Prime[n]][[1,1]],{n,PrimePi[nn]}]
%o A279984 (PARI) lista(nn) = Vec(select(x->isprime(x), Vec(select(x->(!ispower(x)&&x>1), [1..nn])), 1)); \\ _Michel Marcus_, May 04 2018
%o A279984 (Python)
%o A279984 from sympy import prime, mobius, integer_nthroot
%o A279984 def A279984(n): return int((p:=prime(n))-1+sum(mobius(k)*(integer_nthroot(p,k)[0]-1) for k in range(2,p.bit_length()))) # _Chai Wah Wu_, Oct 12 2024
%Y A279984 Cf. A000040, A007916, A279944.
%K A279984 nonn
%O A279984 1,2
%A A279984 _Gus Wiseman_, Dec 24 2016