|
| |
|
|
A006749
|
|
Number of asymmetric polyominoes with n cells.
(Formerly M3906)
|
|
13
|
|
|
|
0, 0, 0, 1, 5, 20, 84, 316, 1196, 4461, 16750, 62878, 237394, 899265, 3422111, 13069026, 50091095, 192583152, 742560511, 2870523142, 11122817672, 43191285751, 168046076423, 654997492842, 2557223459805, 9999080270766, 39152997087077, 153511067364760
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,5
|
|
|
COMMENTS
|
This sequence counts polyominoes whose symmetry group has order 1.
|
|
|
REFERENCES
|
A. R. Conway and A. J. Guttmann, On two-dimensional percolation, J. Phys. A: Math. Gen. 28(1995) 891-904.
D. H. Redelmeier, Counting polyominoes: yet another attack, Discrete Math., 36 (1981), 191-203.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
|
|
|
LINKS
|
Table of n, a(n) for n=1..28.
Tomás Oliveira e Silva, Enumeration of polyominoes
D. H. Redelmeier, Table 3 of Counting polyominoes...
|
|
|
CROSSREFS
|
Cf. A000105, A001168, A006746, A056877, A006748, A056878, A006747, A006749, A006884, A006885, A006877, A006878, A033492.
Sequences classifying polyominoes by symmetry group: A000105, A006746, A006747, A006748, A006749, A056877, A056878, A142886, A144553, A144554.
Sequence in context: A183933 A270322 A056884 * A002213 A099949 A006231
Adjacent sequences: A006746 A006747 A006748 * A006750 A006751 A006752
|
|
|
KEYWORD
|
nonn,nice
|
|
|
AUTHOR
|
N. J. A. Sloane.
|
|
|
EXTENSIONS
|
Extended to n=28 by Tomás Oliveira e Silva.
|
|
|
STATUS
|
approved
|
| |
|
|
