OFFSET
0,2
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
Index entries for linear recurrences with constant coefficients, signature (0,1,-2,2,-1,3,-2,4,-4,2,-3,1,-2,2,-1,1).
FORMULA
G.f.: (1 + x) * (1 - x + x^2) * (1 + 3*x + 8*x^2 + 16*x^3 + 28*x^4 + 37*x^5 + 40*x^6 + 37*x^7 + 28*x^8 + 16*x^9 + 8*x^10 + 3*x^11 + x^12) / ((1 - x)^3 * (1 + x^2)^2 * (1 + x + x^2 + x^3 + x^4)^2). - Colin Barker, Dec 18 2015
MATHEMATICA
CoefficientList[Series[(1 + x) * (1 - x + x^2) * (1 + 3*x + 8*x^2 + 16*x^3 + 28*x^4 + 37*x^5 + 40*x^6 + 37*x^7 + 28*x^8 + 16*x^9 + 8*x^10 + 3*x^11 + x^12) / ((1 - x)^3 * (1 + x^2)^2 * (1 + x + x^2 + x^3 + x^4)^2), {x, 0, 47}], x] (* Stefano Spezia, Dec 22 2022 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved