OFFSET
0,2
REFERENCES
Inorganic Crystal Structure Database: Collection Code 9502.
LINKS
Sean A. Irvine, 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.
FORMULA
G.f.: -(2*x^27 +3*x^25 +3*x^24 +10*x^23 +20*x^22 +43*x^21 +67*x^20 +114*x^19 +151*x^18 +211*x^17 +257*x^16 +303*x^15 +338*x^14 +354*x^13 +358*x^12 +338*x^11 +305*x^10 +261*x^9 +211*x^8 +155*x^7 +116*x^6 +67*x^5 +45*x^4 +18*x^3 +10*x^2 +3*x +1)*(1 +x)*(-1 +x^2)^2 / (-1 +x^4)^2 / (-1 +x^6) / (-1 +x^7) / (-1 +x^9).
MATHEMATICA
Table[SeriesCoefficient[-(2 x^27 + 3 x^25 + 3 x^24 + 10 x^23 + 20 x^22 + 43 x^21 + 67 x^20 + 114 x^19 + 151 x^18 + 211 x^17 + 257 x^16 + 303 x^15 + 338 x^14 + 354 x^13 + 358 x^12 + 338 x^11 + 305 x^10 + 261 x^9 + 211*x^8 + 155 x^7 + 116 x^6 + 67 x^5 + 45 x^4 + 18 x^3 + 10 x^2 + 3 x + 1) (1 + x) (-1 + x^2)^2/(-1 + x^4)^2/(-1 + x^6)/(-1 + x^7)/(-1 + x^9), {x, 0, n}], {n, 0, 47}] (* Michael De Vlieger, Dec 23 2015 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved