A146070 - OEIS

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A146070

Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 5-point zee 1,1 2,1 2,2 2,3 3,3 in any orientation.

1, 1, 5, 1, 9, 25, 101, 401, 3215, 13761, 224503, 1483715, 30996399, 381934429, 12283193557, 226607791453, 11864500856825

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,3

LINKS

Table of n, a(n) for n=1..17.

EXAMPLE

Maximal 8 X 8 example

.0.1.1.0.0.0.1.0

.0.1.0.0.1.1.1.0

.1.1.0.0.1.0.0.1

.0.0.1.0.0.1.1.1

.1.1.1.0.0.1.0.0

.1.0.0.1.0.0.1.1

.0.1.1.1.0.0.1.0

.0.1.0.0.0.1.1.0

CROSSREFS

Sequence in context: A324378 A147404 A254068 * A308504 A040029 A105086

Adjacent sequences: A146067 A146068 A146069 * A146071 A146072 A146073

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 26 2008

STATUS

approved