OFFSET
0,2
COMMENTS
Also coordination sequence T3 for zeolite code UEI. - Sean A. Irvine, Mar 17 2018
REFERENCES
W. M. Meier, D. H. Olson and Ch. Baerlocher, Atlas of Zeolite Structure Types, 4th Ed., Elsevier, 1996.
LINKS
R. W. Grosse-Kunstleve, Table of n, a(n) for n = 0..1000
R. W. Grosse-Kunstleve, Coordination Sequences and Encyclopedia of Integer Sequences
R. W. Grosse-Kunstleve, G. O. Brunner and N. J. A. Sloane, Algebraic Description of Coordination Sequences and Exact Topological Densities for Zeolites, Acta Cryst., A52 (1996), pp. 879-889.
Sean A. Irvine, Generating Functions for Coordination Sequences of Zeolites, after Grosse-Kunstleve, Brunner, and Sloane
International Zeolite Association, Database of Zeolite Structures
FORMULA
From Colin Barker, Feb 13 2018: (Start)
G.f.: (1 + x)*(1 + 3*x + 8*x^2 + 17*x^3 + 29*x^4 + 44*x^5 + 64*x^6 + 84*x^7 + 101*x^8 + 112*x^9 + 116*x^10 + 112*x^11 + 101*x^12 + 84*x^13 + 64*x^14 + 44*x^15 + 29*x^16 + 17*x^17 + 8*x^18 + 3*x^19 + x^20) / ((1 - x)^3*(1 + x^2)*(1 + x + x^2 + x^3 + x^4)*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)^2).
a(n) = -a(n-2) + a(n-5) + 3*a(n-7) + 2*a(n-9) - 2*a(n-12) - 3*a(n-14) - a(n-16) + a(n-19) + a(n-21) for n>21.
(End)
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Title improved by Sean A. Irvine, Mar 16 2018
STATUS
approved