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Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 5-point barb 1,1 1,2 2,2 2,3 3,2 in any orientation.
(history; published version)

#3 by Russ Cox at Sat Mar 31 12:35:09 EDT 2012

AUTHOR

_R. H. Hardin (rhhardin(AT)att.net), _, Oct 27 2008

Discussion

Sat Mar 31

12:35

OEIS Server: https://oeis.org/edit/global/875

#2 by N. J. A. Sloane at Sat Oct 02 03:00:00 EDT 2010

KEYWORD

nonn,new

nonn

AUTHOR

Ron R. H. Hardin (rhhardin(AT)att.net), Oct 27 2008

#1 by N. J. A. Sloane at Fri Jan 09 03:00:00 EST 2009

NAME

Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 5-point barb 1,1 1,2 2,2 2,3 3,2 in any orientation.

DATA

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 7, 7, 21, 21, 61, 61, 403, 403, 3415, 3415, 36395, 36395, 473261, 473261, 8291363, 8291363, 204964495, 204964495

OFFSET

1,11

EXAMPLE

Maximal 11 X 11 example

.0.0.0.1.0.0.0.1.0.0.0

.0.0.1.1.0.0.0.1.1.0.0

.0.1.0.1.1.0.1.1.0.1.0

.1.1.1.0.0.0.0.0.1.1.1

.0.0.1.0.0.0.0.0.1.0.0

.0.0.0.0.0.0.0.0.0.0.0

.0.0.1.0.0.0.0.0.1.0.0

.1.1.1.0.0.0.0.0.1.1.1

.0.1.0.1.1.0.1.1.0.1.0

.0.0.1.1.0.0.0.1.1.0.0

.0.0.0.1.0.0.0.1.0.0.0

KEYWORD

nonn

AUTHOR

Ron Hardin (rhhardin(AT)att.net), Oct 27 2008

STATUS

approved