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 A293511 #5 Oct 20 2017 15:42:12
%S A293511 1,2,3,5,7,11,12,13,17,18,19,20,23,28,29,31,36,37,41,43,44,45,47,50,
%T A293511 52,53,59,61,63,67,68,71,73,75,76,79,83,89,92,97,98,99,100,101,103,
%U A293511 107,109,113,116,117,120,124,127,131,137,139,147,148,149,151,153
%N A293511 Numbers that can be written as a product of distinct squarefree numbers in exactly one way.
%C A293511 First differs from A212166 at a(128) = 363, A212166(128) = 360.
%e A293511 360 is not in the sequence because it has two possible expressions: 2*3*6*10 or 2*6*30.
%t A293511 nn=300;
%t A293511 sqfacs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[sqfacs[n/d],Min@@#>d&]],{d,Select[Rest[Divisors[n]],SquareFreeQ]}]];
%t A293511 Select[Range[nn],Length[sqfacs[#]]===1&]
%Y A293511 Cf. A001055, A005117, A045778, A050320, A050326, A292432, A292444, A293243.
%K A293511 nonn
%O A293511 1,2
%A A293511 _Gus Wiseman_, Oct 11 2017