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 A063407 #7 May 10 2013 12:44:49
%S A063407 0,3,210,21840,4248240,2439718848,4490186803200,21306683553761280,
%T A063407 243362078944548372480,8447714338361362064867328,
%U A063407 916006668995029638614026813440,257020596641378222874290942398955520
%N A063407 Number of cyclic subgroups of order 4 of general affine group AGL(n,2).
%C A063407 Number of cyclic subgroups of order m in general affine group AGL(n,2) is 1/phi(m)*Sum_{d|m} mu(m/d)*b(n,d), where b(n,d) is number of solutions to x^d=1 in AGL(n,2).
%H A063407 V. Jovovic, <a href="/A062766/a062766.pdf">Cycle index of general affine group AGL(n,2)</a>
%F A063407 a(n) = (A063387(n)-A063385(n))/2.
%Y A063407 Cf. A063406-A063413, A063385-A063393, A062710.
%K A063407 nonn
%O A063407 1,2
%A A063407 _Vladeta Jovovic_, Jul 17 2001