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 A317616 #12 Sep 25 2024 10:28:03 %S A317616 12,18,20,24,28,40,44,45,48,50,52,54,56,60,63,68,75,76,80,84,88,90,92, %T A317616 96,98,99,104,112,116,117,120,124,126,132,135,136,140,144,147,148,150, %U A317616 152,153,156,160,162,164,168,171,172,175,176,180,184,188,189,192 %N A317616 Numbers whose prime multiplicities are not pairwise indivisible. %C A317616 The numbers of terms that do not exceed 10^k, for k = 2, 3, ..., are 26, 344, 3762, 38711, 390527, 3915874, 39192197, 392025578, 3920580540, ... . Apparently, the asymptotic density of this sequence exists and equals 0.392... . - _Amiram Eldar_, Sep 25 2024 %H A317616 Amiram Eldar, <a href="/A317616/b317616.txt">Table of n, a(n) for n = 1..10000</a> %e A317616 72 = 2^3 * 3^2 is not in the sequence because 3 and 2 are pairwise indivisible. %t A317616 Select[Range[100],!Select[Tuples[Last/@FactorInteger[#],2],And[UnsameQ@@#,Divisible@@#]&]=={}&] %o A317616 (PARI) is(k) = if(k == 1, 0, my(e = Set(factor(k)[,2])); if(vecmax(e) == 1, 0, for(i = 1, #e, for(j = 1, i-1, if(!(e[i] % e[j]), return(1)))); 0)); \\ _Amiram Eldar_, Sep 25 2024 %Y A317616 Cf. A118914, A124010, A285572, A285573, A303362, A304713, A316475, A317101, A317102. %K A317616 nonn %O A317616 1,1 %A A317616 _Gus Wiseman_, Aug 01 2018