This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A072150 #18 Mar 30 2012 17:38:44 %S A072150 1,3,5,8,10,13,17,18,20,25,26,28,33,33,36,42,41,43,50,49,51,58,56,59, %T A072150 67,64,66,75,72,74,83,79,82,92,87,89,100,95,97,108,102,105,117,110, %U A072150 112,125,118,120,133,125,128,142,133,135,150,141,143,158,148,151 %N A072150 Coordination sequence for AlPO_4-11 structure with respect to node (Y) where decagon, hexagon and square meet and is adjacent to node of type (X). %C A072150 There are three types of nodes in this structure. %C A072150 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 A072150 Joseph Myers, <a href="/A072150/b072150.txt">Table of n, a(n) for n = 0..1000</a> %H A072150 M. E. Davis, <a href="http://dx.doi.org/10.1038/nature00785">Ordered porous materials for emerging applications</a>, Nature, 417 (Jun 20 2002), 813-821 (gives structure). %H A072150 N. J. A. Sloane, <a href="/A072150/a072150.gif">AlPO_4-11 structure, after Davis</a> %H A072150 R. J. Mathar, <a href="/A072150/a072150.ps">Illustration of counts and adjacencies</a> (PostScript) %F A072150 Empirical: G.f 1 +x*(3+5*x+8*x^2+7*x^3+8*x^4+9*x^5+8*x^6+7*x^7+8*x^8+5*x^9+3*x^10) / ( (x^6+x^3+1)*(x-1)^2*(1+x+x^2)^2 ) with a(n)= +a(n-3) +a(n-9) -a(n-12). - R. J. Mathar, Sep 30 2011 %Y A072150 Cf. A072149-A072154. %K A072150 nonn,easy %O A072150 0,2 %A A072150 _N. J. A. Sloane_, Jun 28 2002 %E A072150 More terms from _R. J. Mathar_, Mar 29 2007 %E A072150 Extended by _Joseph Myers_, Sep 29 2011