OFFSET
0,4
LINKS
Jair Taylor, Table of n, a(n) for n = 0..499
Ricardo Gómez Aíza, Symbolic dynamical scales: modes, orbitals, and transversals, arXiv:2009.02669 [math.DS], 2020.
FORMULA
G.f.: (2*x^3 - 2*x^2 - x + 1)/(x^4 + 2*x^3 - x^2 - 2*x + 1).
EXAMPLE
We have a(3) = 3 since 3 = 1 + 2 = 2+1. A(2) = 1 since 2 is the only composition of 2 that does not have more than one 1.
MATHEMATICA
CoefficientList[Series[(2 x^3 - 2 x^2 - x + 1)/(x^4 + 2 x^3 - x^2 - 2 x + 1), {x, 0, 38}], x] (* Michael De Vlieger, Dec 09 2020 *)
PROG
(Sage) R.<x> = PowerSeriesRing(QQ)
f = (2*x^3 - 2*x^2 - x + 1)/(x^4 + 2*x^3 - x^2 - 2*x + 1)
print(f.list())
CROSSREFS
KEYWORD
nonn
AUTHOR
Jair Taylor, Feb 18 2012
STATUS
approved