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 A304817 #9 May 19 2018 12:38:20
%S A304817 1,2,2,2,2,4,2,2,2,4,2,5,2,4,4,2,2,5,2,5,4,4,2,6,2,4,2,5,2,8,2,2,4,4,
%T A304817 4,6,2,4,4,6,2,8,2,5,5,4,2,7,2,5,4,5,2,6,4,6,4,4,2,11,2,4,5,2,4,8,2,5,
%U A304817 4,8,2,8,2,4,5,5,4,8,2,7,2,4,2,11,4,4
%N A304817 Number of divisors of n that are either 1 or not a perfect power.
%C A304817 First differs from A183095 at a(80) = 8, A183095(80) = 7.
%F A304817 a(n) = A183096(n) + 1.
%e A304817 The a(72) = 8 divisors of 72 that are either 1 or not a perfect power are {1, 2, 3, 6, 12, 18, 24, 72}. Missing are {4, 8, 9, 36}.
%t A304817 Table[DivisorSum[n,Boole[GCD@@FactorInteger[#][[All,2]]==1]&],{n,100}]
%o A304817 (PARI) a(n) = sumdiv(n, d, !ispower(d)); \\ _Michel Marcus_, May 19 2018
%Y A304817 Cf. A000005, A001597, A007916, A091050, A183096, A304326, A304362, A304653, A304779, A304819, A304820.
%K A304817 nonn
%O A304817 1,2
%A A304817 _Gus Wiseman_, May 18 2018