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 A266479 #15 Feb 03 2016 17:04:09
%S A266479 0,2,2,6,3,20,4
%N A266479 Number of n-vertex simple graphs G_n for which n does not divide the number of labeled copies of G_n.
%C A266479 Let G_n be an n-vertex simple graph, with a(G_n) automorphisms. Then l(G_n) = n!/a(G_n) is the number of labeled copies of G_n. So a(n) is the number of G_n for which n does not divide l(G_n).
%C A266479 For prime p, a(p) is the number of circulants of order p.
%C A266479 The number of circulants of order n is A049287(n).
%D A266479 John P. McSorley, Smallest labelled class (and largest automorphism group) of a tree T_{s,t} and good labellings of a graph, preprint, (2016).
%D A266479 R. C. Read, R. J. Wilson, An Atlas of Graphs, Oxford Science Publications, Oxford University Press, (1998).
%D A266479 James Turner, Point-symmetric graphs with a prime number of points, Journal of Combinatorial Theory, vol. 3 (1967), 136-145.
%e A266479 If n=3 then both G_3 = K_3 and its complement have a(G_3) = 6, so l(G_3) = 3!/6 = 1, and so 3 does not divide l(G_3); no other graphs G_3 satisfy this, so a(3)=2.
%Y A266479 A000088 minus A266478.
%Y A266479 Cf. A049287.
%K A266479 nonn,hard,more
%O A266479 1,2
%A A266479 _John P. McSorley_, Dec 29 2015