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A146219 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 101-111-010 pattern in any orientation. 0
1, 1, 1, 1, 3, 9, 20, 63, 272, 1557, 10412, 77761, 729051, 8641753, 126757272, 2289847876, 50015283552, 1327280079169, 43398915228962, 1753679030593542, 87293853894564783, 5311141506545315135, 394710940436034575590 (list; graph; refs; listen; history; internal format)
OFFSET

1,5

EXAMPLE

Maximal 8 X 8 example

.0.0.0.1.1.0.0.0

.0.0.1.1.0.0.0.0

.0.1.0.1.1.0.0.0

.1.1.1.0.0.1.0.1

.1.0.1.0.0.1.1.1

.0.0.0.1.1.0.1.0

.0.0.0.0.1.1.0.0

.0.0.0.1.1.0.0.0

CROSSREFS

Sequence in context: A151420 A196294 A196212 * A197403 A128127 A006077

Adjacent sequences:  A146216 A146217 A146218 * A146220 A146221 A146222

KEYWORD

nonn

AUTHOR

R. H. Hardin (rhhardin(AT)att.net)

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Last modified February 13 12:01 EST 2012. Contains 205469 sequences.