A145998 Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 3X3 plus 2,1 2,2 2,3 1,2 3,2.

1, 1, 2, 1, 4, 1, 27, 10, 325, 79, 7166, 1068, 296998, 32561, 25489453, 2049805, 4199698432, 237788014, 1353419597835, 53948164143, 849049576212123, 24026619761999, 1041648115351377356, 20926733702956682

Offset

1,3

Links

Table of n, a(n) for n=1..24.

Example

Maximal 8 X 8 example
.0.1.0.0.0.0.1.0
.1.1.1.0.0.1.1.1
.0.1.0.0.0.0.1.0
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.0.1.0.0.0.0.1.0
.1.1.1.0.0.1.1.1
.0.1.0.0.0.0.1.0

Crossrefs

Sequence in context: A229484 A080212 A186727 * A218952 A177413 A009832

Adjacent sequences: A145995 A145996 A145997 * A145999 A146000 A146001

Keyword

nonn

Author

R. H. Hardin, Oct 26 2008

Status

approved