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A052929 Expansion of (2-3x-x^2)/((1-x^2)(1-3x)). 0
2, 3, 10, 27, 82, 243, 730, 2187, 6562, 19683, 59050, 177147, 531442, 1594323, 4782970, 14348907, 43046722, 129140163, 387420490, 1162261467, 3486784402, 10460353203, 31381059610, 94143178827, 282429536482, 847288609443 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

LINKS

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 915

Index to sequences with linear recurrences with constant coefficients, signature (3,1,-3)

FORMULA

G.f.: -(-2+3*x+x^2)/(-1+x^2)/(-1+3*x)

Recurrence: {a(1)=3, a(2)=10, a(0)=2, -3*a(n)-2*a(n+1)+a(n+2)+2=0}

3^n+Sum(1/2*_alpha^(-n), _alpha=RootOf(-1+_Z^2))

a(n) = 2*A033113(n+1)-3*A033113(n) -A033113(n-1). - R. J. Mathar, Nov 28 2011

MAPLE

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

CROSSREFS

Sequence in context: A005158 A182926 A005225 * A151415 A134588 A000060

Adjacent sequences:  A052926 A052927 A052928 * A052930 A052931 A052932

KEYWORD

easy,nonn

AUTHOR

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

EXTENSIONS

More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jun 05 2000

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Last modified February 15 10:28 EST 2012. Contains 205763 sequences.