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 A172442 #16 Jun 15 2025 18:23:36
%S A172442 1,2,4,6,8,10,32,24,20,30,40,96,512,60,216,2048,150,160,120,140,1536,
%T A172442 32768,864,210,131072,6144,280,480,2560,600,2097152,420,7776,1080,
%U A172442 98304,10240,1050,13824,1120,393216,134217728,840,536870912,2400,1260,55296,7680,163840,6291456
%N A172442 A sixth of the smallest integer for which the number of divisors is the n-th composite.
%F A172442 a(n) = A005179(A002808(n))/6.
%e A172442 The first composite is A002808(1)=4. The smallest integer with 4 divisors is A005179(4) = 6, which divided by 6 yields a(1)=1.
%t A172442 nd[n_]:=Module[{k=6},While[DivisorSigma[0,k]!=n,k+=6];k]; With[{cmps=Select[Range[45],CompositeQ]},(Table[nd[c],{c,cmps}])/6] (* The program generates the first 30 terms of the sequence. *) (* _Harvey P. Dale_, Jun 15 2025 *)
%Y A172442 Cf. A002808, A005179, A061286, A187678.
%K A172442 nonn,less
%O A172442 1,2
%A A172442 _Juri-Stepan Gerasimov_, Mar 12 2011