A147143 - OEIS

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A147143

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1100-0110-0011 pattern in any orientation.

1, 1, 1, 1, 3, 5, 7, 11, 39, 91, 199, 489, 1779, 6121, 21635, 87281, 429831

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

OFFSET

1,5

LINKS

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

EXAMPLE

Maximal 8 X 8 example

.0.0.0.0.1.1.0.0

.0.0.0.1.0.1.1.0

.0.0.0.1.1.0.1.1

.0.1.1.0.1.1.0.1

.1.0.1.1.0.1.1.0

.1.1.0.1.1.0.0.0

.0.1.1.0.1.0.0.0

.0.0.1.1.0.0.0.0

CROSSREFS

Sequence in context: A230139 A242944 A137355 * A006034 A288716 A083840

Adjacent sequences: A147140 A147141 A147142 * A147144 A147145 A147146

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved