A146154 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only either as two by three or three by two blocks.

1, 1, 1, 1, 3, 1, 10, 10, 43, 65, 310, 319, 2668, 3017, 34910, 54223, 689528, 1137739, 18655423, 31210424, 700220638, 1365782613, 38696080322, 86209219516, 3066770236798, 7328473794260, 340900040830525, 897917903090606

Offset

1,5

Links

Table of n, a(n) for n=1..28.

Example

Maximal 8 X 8 example
.1.1.0.1.1.0.1.1
.1.1.0.1.1.0.1.1
.1.1.0.1.1.0.1.1
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.1.1.0.1.1.0.1.1
.1.1.0.1.1.0.1.1
.1.1.0.1.1.0.1.1

Crossrefs

Sequence in context: A185419 A252501 A281000 * A068438 A064060 A176740

Adjacent sequences: A146151 A146152 A146153 * A146155 A146156 A146157

Keyword

nonn

Author

R. H. Hardin, Oct 27 2008

Status

approved