login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A125753 Triangle read by rows: T(n,k) (n>=1) gives the number of n-indecomposable polyominoes with k cells (k >= n). 5
1, 0, 1, 2, 1, 1, 0, 0, 2, 5, 12, 6, 5, 1, 1, 0, 0, 0, 5, 12, 35, 108, 73, 76, 80, 25, 15, 15, 0, 0, 0, 0, 12, 35, 108, 369, 1285, 1044, 1475, 2205, 2643, 983, 1050, 1208, 958, 0, 0, 0, 0, 0, 35, 108, 369, 1285, 4655, 17073, 15980, 26548, 48766, 79579, 99860, 45898, 60433, 89890, 109424, 84312, 0, 0, 0, 0, 0, 0, 108, 369, 1285, 4655, 17073, 63600, 238591, 245955, 458397, 948201, 1857965, 3160371, 4153971, 2217787, 3402761, 5855953, 9067535, 11402651, 9170285, 0, 0, 0, 0, 0, 0, 0, 369, 1285, 4655, 17073, 63600, 238591, 901971, 3426576, 3807508, 7710844, 17354771, 37983463 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
COMMENTS
A polyomino is called n-indecomposable if it cannot be partitioned (along cell boundaries) into two or more polyominoes each with at least n cells.
Row n has 4n-3 terms of which the first n-1 are zero.
For full lists of drawings of these polyominoes for n <= 6, see the links in A125759.
LINKS
N. MacKinnon, Some thoughts on polyomino tilings, Math. Gaz., 74 (1990), 31-33.
Simone Rinaldi and D. G. Rogers, Indecomposability: polyominoes and polyomino tilings, The Mathematical Gazette 92.524 (2008): 193-204.
EXAMPLE
Triangle begins:
1
0,1,2,1,1
0,0,2,5,12,6,5,1,1
0,0,0,5,12,35,108,73,76,80,25,15,15
0,0,0,0,12,35,108,369,1285,1044,1475,2205,2643,983,1050,1208,958
0,0,0,0,0,35,108,369,1285,4655,17073,15980,26548,48766,79579,99860,45898,60433,89890,109424,84312
0,0,0,0,0,0,108,369,1285,4655,17073,63600,238591,245955,458397,948201,1857965,3160371,4153971,2217787,3402761,5855953,9067535,11402651,9170285
0,0,0,0,0,0,0,369,1285,4655,17073,63600,238591,901971,3426576,3807508,7710844,17354771,37983463,...
CROSSREFS
Row sums give A125709. Cf. A125759, A125761, A126742, A126743.
Sequence in context: A179854 A250622 A212551 * A185184 A292894 A147701
KEYWORD
nonn,tabf
AUTHOR
David Applegate and N. J. A. Sloane, Feb 04 2007, Feb 14 2007
EXTENSIONS
Rows 5, 6, 7 and 8 from David Applegate, Feb 16 2007
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 13 21:17 EDT 2024. Contains 374288 sequences. (Running on oeis4.)