

A072149


Coordination sequence for AlPO_411 structure with respect to node (X) where decagon and two hexagons meet.


6



1, 3, 6, 8, 10, 13, 16, 19, 20, 22, 28, 31, 30, 33, 38, 40, 42, 43, 46, 53, 54, 52, 58, 63, 62, 65, 68, 70, 76, 77, 76, 83, 86, 84, 90, 93, 92, 99, 102, 100, 106, 109, 108, 115, 116, 114, 124, 127, 122, 129, 134, 132, 138, 139, 138, 149, 150, 144, 154, 159
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OFFSET

0,2


COMMENTS

There are three types of nodes in this structure.
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.


LINKS

Joseph Myers, Table of n, a(n) for n = 0..1000
M. E. Davis, Ordered porous materials for emerging applications, Nature, 417 (Jun 20 2002), 813821 (gives structure).
N. J. A. Sloane, AlPO_411 structure, after Davis
R. J. Mathar, Illustration of counts and adjacencies (PostScript)


FORMULA

Empirical: G.f. 1 +x*(3 +6*x +11*x^2 +13*x^3 +15*x^4 +15*x^5 +16*x^6 +15*x^7 +15*x^8 +13*x^9 +11*x^10 +6*x^11 +3*x^12) / ( (1+x^2)*(x^6+x^3+1)*(x1)^2*(1+x+x^2)^2 ) with a(n)= a(n2) +a(n3) +a(n5) +a(n9) +a(n11) a(n12) a(n14).  R. J. Mathar, Sep 30 2011


CROSSREFS

Cf. A072150A072154.
Sequence in context: A190325 A064437 A287180 * A001066 A099518 A280106
Adjacent sequences: A072146 A072147 A072148 * A072150 A072151 A072152


KEYWORD

nonn,easy


AUTHOR

N. J. A. Sloane, Jun 28 2002


EXTENSIONS

More terms from R. J. Mathar, Mar 29 2007
Extended by Joseph Myers, Sep 29 2011


STATUS

approved



