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A059682
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Triangle T(n,k) giving number of 2 X k polyominoes with n cells (n >= 2, 1<=k<=n-1).
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0
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1, 0, 1, 0, 1, 3, 0, 0, 2, 3, 0, 0, 1, 6, 5, 0, 0, 0, 2, 11, 5, 0, 0, 0, 1, 10, 19, 7, 0, 0, 0, 0, 3, 22, 28, 7, 0, 0, 0, 0, 1, 15, 52, 40, 9, 0, 0, 0, 0, 0, 3, 45, 90, 53, 9, 0, 0, 0, 0, 0, 1, 21, 119, 158, 69, 11, 0, 0, 0, 0, 0, 0, 4, 73, 257, 238, 86, 11, 0, 0, 0, 0, 0, 0, 1, 28, 237, 505
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OFFSET
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2,6
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REFERENCES
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R. C. Read, Contributions to the cell growth problem, Canad. J. Math., 14 (1962), 1-20.
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LINKS
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Table of n, a(n) for n=2..89.
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FORMULA
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Read, Eq. (8.5), gives g.f.
G.f.: ((y^9-y^8)*x^6+y^8*x^5+(y^7-2*y^6+y^5)*x^4+(y^6-y^3)*x^3+(-y^4+y^2)*x^2+(-y^2-y)*x+1)*y^2*x/((y^3*x^2+(y^2+y)*x-1)*(y*x-1)*(y^2*x-1)*(y^6*x^4+(y^4+y^2)*x^2-1)). - Vladeta Jovovic, Apr 02 2002
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EXAMPLE
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1; 0,1; 0,1,3; 0,0,2,3; ...
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CROSSREFS
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Sequence in context: A120569 A128113 A108930 * A156548 A112883 A117138
Adjacent sequences: A059679 A059680 A059681 * A059683 A059684 A059685
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KEYWORD
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nonn,easy,nice,tabl,changed
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AUTHOR
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N. J. A. Sloane, Feb 05 2001
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EXTENSIONS
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More terms from Vladeta Jovovic, Apr 02 2002
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STATUS
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approved
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