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A052932 Expansion of (1-x)/(1-2x-x^4+x^5). 0
1, 1, 2, 4, 9, 18, 37, 76, 157, 323, 665, 1369, 2819, 5804, 11950, 24604, 50658, 104301, 214748, 442150, 910354, 1874351, 3859149, 7945700, 16359604, 33683205, 69351208, 142788967, 293991838, 605307277, 1246282557, 2566002873 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Equals INVERT transform of (1, 1, 1, 2, 1, 1, 1, 1,...) [From Gary W. Adamson, Apr 27 2009]

LINKS

Table of n, a(n) for n=0..31.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 918

Index entries for linear recurrences with constant coefficients, signature (2,0,0,1,-1).

FORMULA

G.f.: -(-1+x)/(1-2*x+x^5-x^4)

Recurrence: {a(1)=1, a(0)=1, a(3)=4, a(2)=2, a(4)=9, a(n)-a(n+1)-2*a(n+4)+a(n+5)=0}

Sum(-1/11243*(-1630*_alpha-319*_alpha^2-428*_alpha^3+1268*_alpha^4-1807)*_alpha^(-1-n), _alpha=RootOf(1-2*_Z+_Z^5-_Z^4))

MAPLE

spec := [S, {S=Sequence(Prod(Union(Sequence(Z), Prod(Z, Z, Z)), Z))}, unlabeled]: seq(combstruct[count](spec, size=n), n=0..20);

CROSSREFS

Sequence in context: A118255 A206927 A019299 * A018097 A215253 A079580

Adjacent sequences:  A052929 A052930 A052931 * A052933 A052934 A052935

KEYWORD

easy,nonn

AUTHOR

encyclopedia(AT)pommard.inria.fr, Jan 25 2000

EXTENSIONS

More terms from James A. Sellers, Jun 05 2000

STATUS

approved

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Last modified April 23 18:15 EDT 2019. Contains 322387 sequences. (Running on oeis4.)