A146922 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 0110-1111-0110 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 3, 4, 7, 10, 20, 28, 50, 87, 154, 310, 595, 1182, 2674, 5267, 14968, 30208, 93503, 203129, 637081, 1541997

Offset

1,8

Links

Table of n, a(n) for n=1..30.

Example

Maximal 8 X 8 example
.0.0.0.1.1.0.0.0
.0.0.1.1.1.1.0.0
.0.1.0.1.1.0.1.0
.1.1.1.0.0.1.1.1
.1.1.1.0.0.1.1.1
.0.1.0.1.1.0.1.0
.0.0.1.1.1.1.0.0
.0.0.0.1.1.0.0.0

Crossrefs

Sequence in context: A236972 A184351 A343659 * A283363 A236210 A357416

Adjacent sequences: A146919 A146920 A146921 * A146923 A146924 A146925

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved