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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.

A320893 Numbers with an even number of prime factors (counted with multiplicity) that can be factored into squarefree semiprimes (A320911) but cannot be factored into distinct semiprimes (A320892).

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%I A320893 #7 Oct 24 2018 09:49:50
%S A320893 1296,7776,10000,12960,18144,19440,21600,27216,28512,33696,36000,
%T A320893 38416,42336,42768,44064,46656,48600,49248,50544,50625,59616,60000,
%U A320893 66096,73872,75168,77760,80352,89424,95256,95904,98784,100000
%N A320893 Numbers with an even number of prime factors (counted with multiplicity) that can be factored into squarefree semiprimes (A320911) but cannot be factored into distinct semiprimes (A320892).
%C A320893 A semiprime (A001358) is a product of any two not necessarily distinct primes.
%t A320893 sqfsemfacs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[sqfsemfacs[n/d],Min@@#>=d&]],{d,Select[Rest[Divisors[n]],And[SquareFreeQ[#],PrimeOmega[#]==2]&]}]];
%t A320893 strsemfacs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[strsemfacs[n/d],Min@@#>d&]],{d,Select[Rest[Divisors[n]],PrimeOmega[#]==2&]}]];
%t A320893 Select[Range[10000],And[EvenQ[PrimeOmega[#]],strsemfacs[#]=={},sqfsemfacs[#]!={}]&]
%Y A320893 Cf. A001055, A001358, A005117, A006881, A007717, A028260, A318871, A318953, A320655, A320656, A320891, A320892, A320894, A320911, A320912, A320913.
%K A320893 nonn
%O A320893 1,1
%A A320893 _Gus Wiseman_, Oct 23 2018