OFFSET
0,2
COMMENTS
Kekulé numbers for certain benzenoids.
Dimensions of certain Lie algebra (see Landsberg-Manivel reference for precise definition). - N. J. A. Sloane, Oct 15 2007
LINKS
Antoine Bourget, Amihay Hanany, Dominik Miketa, Quiver origami: discrete gauging and folding, arXiv:2005.05273 [hep-th], 2020. See Eq. (3.50), 1st row in Fig. 8, and top box in Fig. 9.
S. J. Cyvin and I. Gutman, Kekulé structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (p. 229).
J. M. Landsberg and L. Manivel, The sextonions and E7 1/2, Adv. Math. 201 (2006), 143-179. [Th. 7.1, case a=0]
Index entries for linear recurrences with constant coefficients, signature (10,-45,120,-210,252,-210,120,-45,10,-1).
FORMULA
G.f.: (x+1)*(x^4+17*x^3+48*x^2+17*x+1)/(x-1)^10. - Colin Barker, Sep 20 2012
a(n) = 10*a(n-1) - 45*a(n-2) + 120*a(n-3) - 210*a(n-4) + 252*a(n-5) - 210*a(n-6) + 120*a(n-7) - 45*a(n-8) + 10*a(n-9) - a(n-10). - Wesley Ivan Hurt, Jun 23 2020
MAPLE
a:=n->(1/4320)*(n+1)*(n+2)^3*(n+3)^3*(n+4)*(2*n+5): seq(a(n), n=0..30);
MATHEMATICA
Table[(1/4320)(n+1)(n+2)^3(n+3)^3(n+4)(2n+5), {n, 0, 30}] (* Harvey P. Dale, Nov 03 2011 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Jun 12 2005
STATUS
approved