OFFSET
0,2
REFERENCES
Gmelin Handbook of Inorg. and Organomet. Chem., 8th Ed., 1994, TYPIX search code (194) hP4.
LINKS
Vincenzo Librandi, 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
Index entries for linear recurrences with constant coefficients, signature (2,-1,0,1,-2,1).
FORMULA
a(0)=1, a(4n)=2*((6n)^2+1), a(4n+2)=18*(2n+1)^2, a(2n+1)=6*(3n^2+3n+1). - Ralf Stephan, Mar 07 2004
G.f.: -(x^3+x^2+3*x+1)*(x^3+3*x^2+x+1) / ((x-1)^3*(x+1)*(x^2+1)). - Colin Barker, Aug 30 2013
MATHEMATICA
CoefficientList[Series[-(x^3 + x^2 + 3 x + 1) (x^3 + 3 x^2 + x + 1)/((x - 1)^3 (x + 1) (x^2 + 1)), {x, 0, 50}], x] (* Vincenzo Librandi, Oct 15 2013 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved