OFFSET
0,2
REFERENCES
Gmelin Handbook of Inorg. and Organomet. Chem., 8th Ed., 1994, TYPIX search code (194) hP4.
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) = (5-(-1)^n+2*(-i)^n+2*i^n+42*n^2)/4 for n>0, where i=sqrt(-1).
a(n) = 2*a(n-1)-a(n-2)+a(n-4)-2*a(n-5)+a(n-6) for n>6.
G.f.: -(x^6+10*x^5+19*x^4+24*x^3+19*x^2+10*x+1) / ((x-1)^3*(x+1)*(x^2+1)). (End)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved