A146255 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 110-111-011 pattern in any orientation.

1, 1, 3, 1, 5, 9, 27, 79, 359, 979, 7545, 28031, 289781, 1662565, 22704081, 184816617, 3459666973, 37715425193, 1006494628185, 14994761556409, 556041103278131, 11700677821513253

Offset

1,3

Links

Table of n, a(n) for n=1..22.

Example

Maximal 8 X 8 example
.0.0.0.0.0.1.1.0
.0.0.0.0.1.1.1.0
.0.1.1.0.1.1.0.0
.1.1.1.0.0.0.1.1
.1.1.0.0.0.1.1.1
.0.0.1.1.0.1.1.0
.0.1.1.1.0.0.0.0
.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A201751 A202504 A146916 * A331432 A122366 A228781

Adjacent sequences: A146252 A146253 A146254 * A146256 A146257 A146258

Keyword

nonn

Author

R. H. Hardin

Status

approved