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 A328742 #10 Nov 03 2019 16:04:04
%S A328742 1,1,0,1,2,8,17,52,130,363,968,2684,7338,20440,56836,159424,448130,
%T A328742 1266080,3586479,10195276,29054568,83018624,237729932,682196948,
%U A328742 1961301330,5648590728,16293970840,47071589049,136171269780,394427456120,1143839302904,3320824711204
%N A328742 Number of n-bead necklace structures which are not self-equivalent under a nonzero rotation using a maximum of three different colored beads.
%C A328742 Permuting the colors does not change the structure.
%H A328742 Andrew Howroyd, <a href="/A328742/b328742.txt">Table of n, a(n) for n = 0..200</a>
%F A328742 a(n) = Sum_{k=1..3} A327693(n, k) for n > 0.
%F A328742 a(p) = A002075(p) for prime p >= 5.
%Y A328742 Cf. A002075, A002076, A327693, A328740.
%K A328742 nonn
%O A328742 0,5
%A A328742 _Andrew Howroyd_, Oct 26 2019