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A145817 Number of islands of ones fitting in an n X n array symmetric under 180 degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally. 0
0, 0, 2, 2, 4, 6, 8, 10, 14, 14, 19, 24, 26, 30, 38 (list; graph; refs; listen; history; internal format)
OFFSET

1,3

EXAMPLE

8 X 8 example with 10 islands

.1.0.1.1.1.0.0.0

.1.0.0.0.0.1.1.1

.1.0.1.1.1.0.0.0

.0.0.0.0.0.1.1.1

.1.1.1.0.0.0.0.0

.0.0.0.1.1.1.0.1

.1.1.1.0.0.0.0.1

.0.0.0.1.1.1.0.1

CROSSREFS

Sequence in context: A049625 A202102 A118303 * A145809 A116859 A179999

Adjacent sequences:  A145814 A145815 A145816 * A145818 A145819 A145820

KEYWORD

nonn

AUTHOR

R. H. Hardin (rhhardin(AT)att.net), Oct 20 2008

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Last modified February 15 13:18 EST 2012. Contains 205796 sequences.