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A052538
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Expansion of (1-x)/(1-2x-3x^2+3x^3).
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1
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1, 1, 5, 10, 32, 79, 224, 589, 1613, 4321, 11714, 31552, 85283, 230080, 621353, 1677097, 4528013, 12223258, 32999264, 89084263, 240496544, 649248085, 1752733013, 4731720649, 12773896082, 34484755072, 93096036443
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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LINKS
| INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 469
Index to sequences with linear recurrences with constant coefficients, signature (2,3,-3).
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FORMULA
| G.f.: -(-1+x)/(1-2*x-3*x^2+3*x^3)
Recurrence: {a(1)=1, a(0)=1, a(2)=5, 3*a(n)-3*a(n+1)-2*a(n+2)+a(n+3)=0}
Sum(-1/107*(-13-38*_alpha+33*_alpha^2)*_alpha^(-1-n), _alpha=RootOf(1-2*_Z-3*_Z^2+3*_Z^3))
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MAPLE
| spec := [S, {S=Sequence(Prod(Z, Union(Z, Z, Z, Sequence(Z))))}, unlabeled]: seq(combstruct[count](spec, size=n), n=0..20);
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CROSSREFS
| Sequence in context: A174467 A005201 A094234 * A073705 A121158 A032772
Adjacent sequences: A052535 A052536 A052537 * A052539 A052540 A052541
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KEYWORD
| easy,nonn
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AUTHOR
| encyclopedia(AT)pommard.inria.fr, Jan 25 2000
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EXTENSIONS
| More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jun 08 2000
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