login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the 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.
0
1, 0, 1, 0, 2, 2, 0, 5, 10, 5, 0, 12, 66, 55, 12, 0, 35, 415, 695, 285, 35, 0, 108, 2844, 8227, 6080, 1446, 108, 0, 369, 19875, 95697, 113418, 46441, 7140, 369, 0, 1285, 142046, 1092358, 1964647, 1238196, 320074, 34385, 1285, 0, 4655, 1026197, 12351464
OFFSET
1,5
COMMENTS
For n > 1, T(n, 2) = T(n, n) = A000105(n).
EXAMPLE
RBRG is considered the same as BRBG, but different from RBGR.
1; 0,1; 0,2,2; 0,5,10,5; ...
PROG
See the link for MATLAB code.
CROSSREFS
Cf. A000105.
Sequence in context: A356035 A321127 A222128 * A355570 A168505 A100334
KEYWORD
nonn,tabl,less
AUTHOR
David Wasserman, Oct 30 2003
STATUS
approved