A145953 Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a zee 1,1 1,2 2,2 2,3 in any orientation.

1, 1, 1, 1, 7, 11, 159, 327, 5133, 13861, 849385, 3108015, 457381857, 2235253839, 607242639437, 3907846853149, 2764340116761305, 23642760363071615, 40211844595990066697, 457112748895519083981, 1725707575657931227023395

Offset

1,5

Links

Table of n, a(n) for n=1..21.

Example

Maximal 8 X 8 example
.0.1.0.0.0.0.1.0
.1.1.0.0.0.0.1.1
.1.0.0.0.0.0.0.1
.0.1.0.0.0.0.1.0
.1.1.0.0.0.0.1.1
.1.0.0.0.0.0.0.1
.0.1.1.0.0.1.1.0
.1.1.0.0.0.0.1.1

Crossrefs

Sequence in context: A130704 A335813 A038543 * A154303 A128340 A106716

Adjacent sequences: A145950 A145951 A145952 * A145954 A145955 A145956

Keyword

nonn

Author

R. H. Hardin, Oct 25 2008

Status

approved