A059483 Triangle T(n,k) = number of fixed 2 X n polyominoes with k cells = coefficient of x^n*y^k in (1+x*y)/(1-x*y-x*y^2-x^2*y^3)-1, read by rows in order 00, 10, 01, 20, 11, 02, ...

0, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 2, 1, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0, 2, 6, 0, 0, 0, 0, 0, 0, 0, 0, 12, 1, 0, 0, 0, 0, 0, 0, 0, 0, 2, 18, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 38, 1, 0, 0, 0, 0

Offset

0,5

Links

Table of n, a(n) for n=0..90.

R. C. Read, Contributions to the cell growth problem, Canad. J. Math., 14 (1962), 1-20.

N. J. A. Sloane, Transforms

Maple

read transforms; (1+x*y)/(1-x*y-x*y^2-x^2*y^3)-1; SERIES2(%, x, y, 12): SERIES2TOLIST(%, x, y, 12);

Crossrefs

Sequence in context: A369165 A056170 A248395 * A067618 A279255 A055029

Adjacent sequences: A059480 A059481 A059482 * A059484 A059485 A059486

Keyword

nonn,tabl,easy

Author

N. J. A. Sloane, Feb 04 2001

Extensions

a(84)-a(86) corrected by Sean A. Irvine, Sep 25 2022

Status

approved