

A059682


Triangle T(n,k) giving number of 2 X k polyominoes with n cells (n >= 2, 1<=k<=n1).


0



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

2,6


REFERENCES

R. C. Read, Contributions to the cell growth problem, Canad. J. Math., 14 (1962), 120.


LINKS

Table of n, a(n) for n=2..89.


FORMULA

Read, Eq. (8.5), gives g.f.
G.f.: ((y^9y^8)*x^6+y^8*x^5+(y^72*y^6+y^5)*x^4+(y^6y^3)*x^3+(y^4+y^2)*x^2+(y^2y)*x+1)*y^2*x/((y^3*x^2+(y^2+y)*x1)*(y*x1)*(y^2*x1)*(y^6*x^4+(y^4+y^2)*x^21)).  Vladeta Jovovic, Apr 02 2002


EXAMPLE

1; 0,1; 0,1,3; 0,0,2,3; ...


CROSSREFS

Sequence in context: A120569 A128113 A108930 * A156548 A112883 A117138
Adjacent sequences: A059679 A059680 A059681 * A059683 A059684 A059685


KEYWORD

nonn,easy,nice,tabl


AUTHOR

N. J. A. Sloane, Feb 05 2001


EXTENSIONS

More terms from Vladeta Jovovic, Apr 02 2002


STATUS

approved



