A146231 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1100-1111 pattern in any orientation.

1, 1, 1, 5, 17, 35, 163, 959, 6943, 61513, 740733, 9820359, 193942865, 4360418313, 137513801459

Offset

1,4

Links

Table of n, a(n) for n=1..15.

Example

Maximal 8 X 8 example
.1.1.0.0.1.1.1.1
.1.1.1.1.0.0.1.1
.0.0.0.0.0.0.0.0
.1.1.0.0.1.1.1.1
.1.1.1.1.0.0.1.1
.0.0.0.0.0.0.0.0
.1.1.0.0.1.1.1.1
.1.1.1.1.0.0.1.1

Crossrefs

Sequence in context: A297520 A026394 A004538 * A186029 A083048 A123669

Adjacent sequences: A146228 A146229 A146230 * A146232 A146233 A146234

Keyword

nonn

Author

R. H. Hardin

Status

approved