%I
%S 1,3,5,6,7,9,11,13,16,19,20,20,22,25,27,29,32,34,34,35,38,41,43,45,47,
%T 48,49,51,54,57,59,60,61,63,65,67,70,73,74,74,76,79,81,83,86,88,88,89,
%U 92,95,97,99,101,102,103,105,108,111,113,114,115,117,119,121,124
%N Coordination sequence for VPl5 structure with respect to node (Y) where 18gon, hexagon and square meet.
%C There are two types of nodes in this structure.
%C The coordination sequence with respect to a particular node gives the number of nodes that can be reached from that node in n steps along edges.
%D M. E. Davis, Ordered porous materials for emerging applications, Nature, 417 (Jun 20 2002), 813821 (gives structure).
%H Joseph Myers, <a href="/A072153/b072153.txt">Table of n, a(n) for n = 0..1000</a>
%H N. J. A. Sloane, <a href="/A072152/a072152.gif">VPl5 structure, after Davis</a>
%F Empirical G.f.: (x^2+x+1)^2*(x^6+x^3+1)/((x1)^2*(x^2+1)*(x^6+x^5+x^4+x^3+x^2+x+1)). [_Colin Barker_, Nov 18 2012]
%Y Cf. A072149A072154.
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, Jun 28 2002
%E Extended by _Joseph Myers_, Sep 30 2011
