login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

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

LINKS

Table of n, a(n) for n=1..49.

D. Wasserman, Illustrations of colored pentominoes and hexominoes

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: A329687 A321127 A222128 * A168505 A100334 A277295

Adjacent sequences:  A088969 A088970 A088971 * A088973 A088974 A088975

KEYWORD

nonn,tabl,less

AUTHOR

David Wasserman, Oct 30 2003

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 20 11:42 EDT 2021. Contains 347584 sequences. (Running on oeis4.)