%I #18 Apr 10 2018 08:26:35
%S 1,4,11,23,46,70,100,131,177,230,280,332,395,471,554,620,714,797,909,
%T 998,1120,1226,1353,1453,1618,1736,1906,1995,2195,2336,2540,2646,2861,
%U 3011,3268,3374,3642,3771,4071,4194,4502,4648,4961,5083,5456,5600,5976
%N Coordination sequence T2 for Cordierite.
%D Inorganic Crystal Structure Database: Collection Code 30947.
%H Sean A. Irvine, <a href="/A008252/b008252.txt">Table of n, a(n) for n = 0..1000</a>
%H R. W. Grosse-Kunstleve, <a href="/A005897/a005897.html">Coordination Sequences and Encyclopedia of Integer Sequences</a>
%H R. W. Grosse-Kunstleve, G. O. Brunner and N. J. A. Sloane, <a href="http://neilsloane.com/doc/ac96cs/">Algebraic Description of Coordination Sequences and Exact Topological Densities for Zeolites</a>, Acta Cryst., A52 (1996), pp. 879-889.
%H Sean A. Irvine, <a href="/A008000/a008000_1.pdf">Generating Functions for Coordination Sequences of Zeolites, after Grosse-Kunstleve, Brunner, and Sloane</a>
%F G.f.: (1 + 5*x + 16*x^2 + 40*x^3 + 88*x^4 + 159*x^5 + 252*x^6 + 359*x^7 + 459*x^8 + 535*x^9 + 566*x^10 + 547*x^11 + 481*x^12 + 381*x^13 + 272*x^14 + 167*x^15 + 92*x^16 + 38*x^17 + 10*x^18 - x^19 - x^20 - 2*x^21) / ((1 - x)^3 * (1 + x)^3 * (1 - x + x^2) * (1 + x^2)^2 * (1 + x + x^2 + x^3 + x^4)^2). - _Colin Barker_, Dec 23 2015
%K nonn
%O 0,2
%A _Ralf W. Grosse-Kunstleve_