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 A086683 #4 Jul 08 2018 21:29:50
%S A086683 1,3,45,6579,10763361,169457722083,25015772614247325,
%T A086683 34185618461516789943315,429210477536564292209765507601,
%U A086683 49269609804781974438694405096704997875,51537752073201133103646184766360896456864366605,490093718158481239203594498957165010835856989328505008243
%N A086683 Number of n X n {-1,0,1} matrices modulo cyclic permutations of the rows.
%H A086683 Andrew Howroyd, <a href="/A086683/b086683.txt">Table of n, a(n) for n = 0..40</a>
%F A086683 a(n) = (1/n)*Sum_{ d divides n } phi(d)*3^(n^2/d) for n > 0.
%o A086683 (PARI) a(n) = if(n<1, n==0, sumdiv(n, d, eulerphi(d)*3^(n^2/d))/n);
%Y A086683 Cf. A086675, A060336.
%K A086683 nonn
%O A086683 0,2
%A A086683 Yuval Dekel (dekelyuval(AT)hotmail.com), Jul 28 2003
%E A086683 a(0)=1 prepended and terms a(7) and beyond from _Andrew Howroyd_, Jul 08 2018