OFFSET
0,2
COMMENTS
Needs a b-file (not based on any conjectures, of course). - N. J. A. Sloane, Dec 18 2015
LINKS
V. A. Blatov, A. P. Shevchenko, D. M. Proserpio, Applied Topological Analysis of Crystal Structures with the Program Package ToposPro, Cryst. Growth Des. 2014, 14, 3576-3586. See Table I.
FORMULA
Empirical: Sum_{k=0..n} [(1903/72) + (3/8)*(-1)^k +19*KroneckerDelta[k,0] - 8*KroneckerDelta[k,1] - 12*KroneckerDelta[k,2] + ((k+1)/12)*(187*k-273) - (32*sqrt(3)/27)*((13/2)*cos((4k+1)*Pi/6) + sin(2k*Pi/3)) - (3*sqrt(26)/2)*(-1)^n*cos(k*Pi/2 + arctan(1/5)) - (3/4)*i^k*(1+(-1)^k)*(k+2)].- G. C. Greubel, Dec 18 2015
Empirical g.f.: (1 +12*x +51*x^2 +130*x^3 +243*x^4 +350*x^5 +450*x^6 +418*x^7 +327*x^8 +182*x^9 +51*x^10 +16*x^11 -7*x^12 +8*x^13 +12*x^14) / ((1 -x)^4*(1 +x)*(1 +x^2)^2*(1 +x +x^2)^2). - Colin Barker, Dec 19 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 15 2015
STATUS
approved