A146010 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 3X3 tee 1,1 1,2 1,3 2,2 3,2 in any orientation.

1, 1, 1, 1, 1, 1, 2, 5, 10, 17, 41, 113, 371, 1287, 4551, 19076, 90597, 483533, 2906704, 18699832, 136658284, 1121369297, 10362476826, 106541327541, 1220122346197, 15486094270737, 222171208299640, 3540873297034591, 63467027877319177

Offset

1,7

Links

Table of n, a(n) for n=1..29.

Example

Maximal 8 X 8 example
.0.0.0.1.0.0.0.0
.0.0.0.1.1.1.0.0
.0.0.0.1.0.0.1.0
.1.1.1.0.0.0.1.0
.0.1.0.0.0.1.1.1
.0.1.0.0.1.0.0.0
.0.0.1.1.1.0.0.0
.0.0.0.0.1.0.0.0

Crossrefs

Sequence in context: A173112 A213299 A172114 * A077631 A350878 A354246

Adjacent sequences: A146007 A146008 A146009 * A146011 A146012 A146013

Keyword

nonn

Author

R. H. Hardin, Oct 26 2008

Status

approved