A146821 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1110-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 3, 17, 41, 79, 223, 801, 2615, 9741, 48585, 263431, 1569087, 9472069, 65995437, 509339343, 4406836165

Offset

1,7

Links

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

Example

Maximal 8 X 8 example
.1.0.0.0.0.1.1.1
.1.1.0.0.1.1.1.0
.1.1.0.0.1.0.0.0
.0.1.1.0.0.0.0.0
.0.0.0.0.0.1.1.0
.0.0.0.1.0.0.1.1
.0.1.1.1.0.0.1.1
.1.1.1.0.0.0.0.1

Crossrefs

Sequence in context: A107147 A049078 A209544 * A181981 A089637 A135471

Adjacent sequences: A146818 A146819 A146820 * A146822 A146823 A146824

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved