A072153 - OEIS

%I #16 Jan 09 2025 08:01:28

%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 VPl-5 structure with respect to node (Y) where 18-gon, 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.

%H Joseph Myers, <a href="/A072153/b072153.txt">Table of n, a(n) for n = 0..1000</a>

%H M. E. Davis, <a href="https://doi.org/10.1038/nature00785">Ordered porous materials for emerging applications</a>, Nature, 417 (Jun 20 2002), 813-821 (gives structure).

%H N. J. A. Sloane, <a href="/A072152/a072152.gif">VPl-5 structure, after Davis</a>

%F Empirical G.f.: (x^2+x+1)^2*(x^6+x^3+1)/((x-1)^2*(x^2+1)*(x^6+x^5+x^4+x^3+x^2+x+1)). [_Colin Barker_, Nov 18 2012]

%Y Cf. A072149, A072150, A072151, A072152, A072154.

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_, Jun 28 2002

%E Extended by _Joseph Myers_, Sep 30 2011