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A146012 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 3X3 tee 1,1 1,2 1,3 2,2 3,2 in any orientation. 0
1, 1, 1, 1, 1, 3, 10, 21, 36, 85, 291, 923, 3735, 16127, 78677, 397086, 2338305, 14669249, 110594974, 880940226, 8350924404, 83469619311, 977221485292, 12070642055579 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Table of n, a(n) for n=1..24.

EXAMPLE

Maximal 8 X 8 example

.0.0.0.1.1.1.0.0

.0.0.0.0.1.0.0.0

.1.0.0.0.1.0.0.0

.1.1.1.0.0.0.0.1

.1.0.0.0.0.1.1.1

.0.0.0.1.0.0.0.1

.0.0.0.1.0.0.0.0

.0.0.1.1.1.0.0.0

CROSSREFS

Sequence in context: A194141 A281153 A014105 * A027917 A038347 A338089

Adjacent sequences:  A146009 A146010 A146011 * A146013 A146014 A146015

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 26 2008

STATUS

approved

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Last modified April 22 07:26 EDT 2021. Contains 343163 sequences. (Running on oeis4.)