OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Eiichi Bannai and Michio Ozeki, Construction of Jacobi forms from certain combinatorial polynomials, Proc. Japan Acad. A72 12-15 1996.
Manabu Oura, Molien Series Related to Certain Finite Unitary Reflection Groups, Kyushu Journal of Mathematics 50.2 (1996): 297-310. See the example of Group No. 9.
G. C. Shephard and J. A. Todd, Finite unitary reflection groups, Canadian J. Math. 6, (1954), 274--304. MR0059914 (15,600b).
Index entries for linear recurrences with constant coefficients, signature (2,-1,2,-4,2,-1,2,-1).
FORMULA
G.f.: (1+8*x+21*x^2+58*x^3+47*x^4+35*x^5+21*x^6+x^7)/(1-x)^2/(1-x^3)^2
MAPLE
(1+8*x+21*x^2+58*x^3+47*x^4+35*x^5+21*x^6+x^7)/(1-x)^2/(1-x^3)^2;
MATHEMATICA
CoefficientList[Series[(1 + 8 x + 21 x^2 + 58 x^3 + 47 x^4 + 35 x^5 + 21 x^6 + x^7) / (1 - x)^2 / (1 - x^3)^2, {x, 0, 60}], x] (* Vincenzo Librandi, Aug 15 2013 *)
PROG
(PARI) a(n)=(32/3*n^3 +8*n^2 + 19/3*n +2+if(n%3==2, -16*((n-2)/3)-12, 8*floor(n/3)+(n%3)*2+1))/3 /* Ralf Stephan, Aug 15 2013 */
(PARI) x='x+O('x^66); Vec( (1+8*x+21*x^2+58*x^3+47*x^4+35*x^5+21*x^6+x^7)/(1-x)^2/(1-x^3)^2 ) \\ Joerg Arndt, Aug 15 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved