A146676 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1100-0111-1100 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 18, 9, 118, 25, 954, 93, 7545, 633, 121807, 8913, 3109792, 136370, 104854969, 2447483, 4391577608, 66801664, 267821817268, 2869431585

Offset

1,9

Links

Table of n, a(n) for n=1..26.

Example

Maximal 9 X 9 example
.0.1.0.1.0.1.0.1.0
.0.1.0.1.1.1.0.1.0
.1.1.1.0.1.0.1.1.1
.1.0.1.0.1.0.1.0.1
.0.0.0.0.0.0.0.0.0
.1.0.1.0.1.0.1.0.1
.1.1.1.0.1.0.1.1.1
.0.1.0.1.1.1.0.1.0
.0.1.0.1.0.1.0.1.0

Crossrefs

Sequence in context: A233471 A040309 A373404 * A147438 A033965 A146415

Adjacent sequences: A146673 A146674 A146675 * A146677 A146678 A146679

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved