%N a(n) = number of elements of order n in simple group L_2(7) of order 168.
%D H. Ferguson and C. Ferguson, Eightfold way: the sculpture, pp. 133-173 in S. Levy, ed., The Eightfold Way, Cambridge, 1999. (Beware errors!)
%H <a href="/index/Gre#groups">Index entries for sequences related to groups</a>
%o (MAGMA) t1:=[0 : n in [1..7]]; G:=PSL(2,7); for g in G do t1[Order(g)]:=t1[Order(g)]+1; end for; t1; (see A145437 for a much better program!)
%A _N. J. A. Sloane_, Apr 06 2009