A146858 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1101-0111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 5, 17, 43, 153, 711, 4787, 36997, 323223, 3456487, 47029493, 778875019, 15666901145, 390119856899, 11978383979491, 447614381910255, 20341843546977767

Offset

1,6

Links

Table of n, a(n) for n=1..21.

Example

Maximal 8 X 8 example
.0.0.1.0.1.1.0.0
.0.0.1.1.1.0.0.0
.1.1.0.0.1.0.0.1
.0.1.0.0.0.1.1.1
.1.1.1.0.0.0.1.0
.1.0.0.1.0.0.1.1
.0.0.0.1.1.1.0.0
.0.0.1.1.0.1.0.0

Crossrefs

Sequence in context: A046916 A089527 A146778 * A146183 A163424 A294102

Adjacent sequences: A146855 A146856 A146857 * A146859 A146860 A146861

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved