OFFSET
0,3
LINKS
Dragomir Z. Djokovic, Poincaré series [or Poincare series] of some pure and mixed trace algebras of two generic matrices. See Table 9.
Index entries for linear recurrences with constant coefficients, signature (0,4,4,-6,-16,-2,24,23,-12,-36,-12,23,24,-2,-16,-6,4,4,0,-1).
FORMULA
G.f.: (1 - x^2 + x^4)/((1 - x^2)^4*(1 - x^3)^4). - Robin Visser, Mar 13 2024
PROG
(Sage)
def a(n):
if n==0: return 1
f = (1-x^2+x^4)/((1-x^2)^4*(1-x^3)^4)
return f.taylor(x, 0, n).coefficient(x^n) # Robin Visser, Mar 13 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Dec 21 2006
EXTENSIONS
More terms from Robin Visser, Mar 13 2024
STATUS
approved