OFFSET
0,6
LINKS
D. Battaglino, J. M. Fedou, S. Rinaldi and S. Socci, The number of k-parallelogram polyominoes, FPSAC 2013 Paris, France DMTCS Proc. AS, 2013, 1143-1154. hal-01229685.
Index entries for linear recurrences with constant coefficients, signature (9,-32,57,-53,24,-4).
FORMULA
G.f.: x^5*(2-5*x+3*x^2-x^3)/((1-x)^2*(1-2*x)^2*(1-3*x+x^2)).
a(n) = 9*a(n-1)-32*a(n-2)+57*a(n-3)-53*a(n-4)+24*a(n-5)-4*a(n-6). - Wesley Ivan Hurt, Jun 20 2022
MATHEMATICA
CoefficientList[Series[x^5*(2 - 5*x + 3*x^2 - x^3)/((1 - x)^2*(1 - 2*x)^2*(1 - 3*x + x^2)), {x, 0, 34}], x] (* Amiram Eldar, Oct 08 2020 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Oct 04 2013
STATUS
approved