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.

1, 1, 1, 1, 1, 3, 10, 21, 36, 85, 291, 923, 3735, 16127, 78677, 397086, 2338305, 14669249, 110594974, 880940226, 8350924404, 83469619311, 977221485292, 12070642055579

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: A281153 A014105 A354329 * A027917 A038347 A338089

Adjacent sequences: A146009 A146010 A146011 * A146013 A146014 A146015

Keyword

nonn

Author

R. H. Hardin, Oct 26 2008

Status

approved