A088972 - OEIS

A088972

Triangle read by rows: colored polyominoes. For n >= 1, 1 <= k <= n, T(n, k) is the number of k-colored n-celled polyominoes, counted up to rotation, reflection and permutation of the colors. Adjacent cells must be different colors. T(n, k) counts only polyominoes that include all k colors.

%I #6 Dec 17 2017 07:25:26

%S 1,0,1,0,2,2,0,5,10,5,0,12,66,55,12,0,35,415,695,285,35,0,108,2844,

%T 8227,6080,1446,108,0,369,19875,95697,113418,46441,7140,369,0,1285,

%U 142046,1092358,1964647,1238196,320074,34385,1285,0,4655,1026197,12351464

%N Triangle read by rows: colored polyominoes. For n >= 1, 1 <= k <= n, T(n, k) is the number of k-colored n-celled polyominoes, counted up to rotation, reflection and permutation of the colors. Adjacent cells must be different colors. T(n, k) counts only polyominoes that include all k colors.

%C For n > 1, T(n, 2) = T(n, n) = A000105(n).

%H D. Wasserman, <a href="http://home.earthlink.net/~dwasserm/Polyforms/ColoredPolyominoes.html">Illustrations of colored pentominoes and hexominoes</a>

%e RBRG is considered the same as BRBG, but different from RBGR.

%e 1; 0,1; 0,2,2; 0,5,10,5; ...

%o See the link for MATLAB code.

%Y Cf. A000105.

%K nonn,tabl,less

%O 1,5

%A _David Wasserman_, Oct 30 2003