OFFSET
0,3
LINKS
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 1041
Index entries for linear recurrences with constant coefficients, signature (1,2,0,-1).
FORMULA
G.f.: -(-1+x)/(1-2*x^2+x^4-x).
Recurrence: {a(0)=1, a(1)=0, a(2)=2, a(3)=2, a(n)-2*a(n+2)-a(n+3)+a(n+4)=0}.
Sum_(1/283*(29*_alpha+28*_alpha^3-76*_alpha^2+55)*_alpha^(-1-n), _alpha=RootOf(1-2*_Z^2+_Z^4-_Z)).
a(n)+a(n-1) = A052535(n). - R. J. Mathar, Nov 28 2011
MAPLE
spec := [S, {S=Sequence(Prod(Union(Prod(Union(Sequence(Z), Z), Z), Z), Z))}, unlabeled ]: seq(combstruct[count ](spec, size=n), n=0..20);
MATHEMATICA
CoefficientList[Series[(1-x)/(1-x-2x^2+x^4), {x, 0, 40}], x] (* or *) LinearRecurrence[{1, 2, 0, -1}, {1, 0, 2, 2}, 40] (* Harvey P. Dale, Oct 20 2017 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
encyclopedia(AT)pommard.inria.fr, Jan 25 2000
EXTENSIONS
More terms from James A. Sellers, Jun 05 2000
STATUS
approved