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A144553 Number of polyominoes with n cells that have precisely the symmetry group of order 4 generated by 90 degree rotations. 10
0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 3, 2, 0, 0, 12, 7, 0, 0, 44, 25, 0, 0, 165, 90, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,12

REFERENCES

D. H. Redelmeier, Counting polyominoes: yet another attack, Discrete Math., 36 (1981), 191-203.

LINKS

Table of n, a(n) for n=1..27.

Tomás Oliveira e Silva, Enumeration of polyominoes

D. H. Redelmeier, Table 3 of Counting polyominoes...

CROSSREFS

Sequences classifying polyominoes by symmetry group: A000105, A006746, A006747, A006748, A006749, A056877, A056878, A142886, A144553, A144554.

Sequence in context: A246159 A059033 A133209 * A187130 A187145 A131290

Adjacent sequences:  A144550 A144551 A144552 * A144554 A144555 A144556

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane, Jan 01 2009

STATUS

approved

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Last modified August 24 00:01 EDT 2016. Contains 275767 sequences.