OFFSET
0,2
REFERENCES
Gmelin Handbook of Inorg. and Organomet. Chem., 8th Ed., 1994, TYPIX search code (205) cP12
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
From Colin Barker, Sep 09 2014: (Start)
a(n) = (13+3*(-1)^n-2*(1+(-1)^n)*n-2*(-18+(-1)^n)*n^2)/8 for n>0.
a(n) = 3*a(n-2)-3*a(n-4)+a(n-6) for n>6.
G.f.: -(x^6+6*x^5+17*x^4+26*x^3+15*x^2+6*x+1) / ((x-1)^3*(x+1)^3). (End)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved