%I A008579
%S A008579 1,4,8,14,18,22,28,30,38,38,48,46,58,54,68,62,78,70,88,
%T A008579 78,98,86,108,94,118,102,128,110,138,118,148,126,158,
%U A008579 134,168,142,178,150,188,158,198,166,208,174,218,182
%N A008579 Coordination sequence for planar net 3.6.3.6. Spherical growth function 
               for certain reflection group in plane.
%C A008579 Interesting because coefficients never become monotonic.
%D A008579 P. de la Harpe, Topics in Geometric Group Theory, Univ. Chicago Press, 
               2000, p. 161 (but beware errors).
%H A008579 T. D. Noe, <a href="b008579.txt">Table of n, a(n) for n=0..1000</a>
%F A008579 G.f.: (1+2*x)*(1+2*x+2*x^2+2*x^3-x^4)/(1-x^2)^2.
%p A008579 f := n->if n mod 2 = 0 then 10*(n/2)-2 else 8*(n-1)/2+6 fi;
%Y A008579 Sequence in context: A114971 A036312 A024805 this_sequence A022804 A067699 
               A066941
%Y A008579 Adjacent sequences: A008576 A008577 A008578 this_sequence A008580 A008581 
               A008582
%K A008579 nonn,nice,easy
%O A008579 0,2
%A A008579 N. J. A. Sloane (njas(AT)research.att.com).