|
| |
|
|
A072149
|
|
Coordination sequence for AlPO_4-11 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
(list; graph; refs; listen; history; internal format)
|
|
|
|
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), 813-821 (gives structure).
N. J. A. Sloane, AlPO_4-11 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)*(x-1)^2*(1+x+x^2)^2 ) with a(n)= -a(n-2) +a(n-3) +a(n-5) +a(n-9) +a(n-11) -a(n-12) -a(n-14). - R. J. Mathar, Sep 30 2011
|
|
|
CROSSREFS
| Cf. A072150-A072154.
Sequence in context: A189937 A190325 A064437 * A001066 A099518 A184855
Adjacent sequences: A072146 A072147 A072148 * A072150 A072151 A072152
|
|
|
KEYWORD
| nonn,easy
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Jun 28 2002
|
|
|
EXTENSIONS
| More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 29 2007
Extended by Joseph Myers (jsm(AT)polyomino.org.uk), Sep 29 2011
|
| |
|
|
