A146387 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 0110-1111 pattern in any orientation.

1, 1, 1, 1, 1, 4, 7, 18, 33, 62, 229, 826, 2874, 11455, 45319, 227245, 1250786, 7902554, 51293369, 381222454, 3041924174, 28668489843, 286940122325, 3336283386716

Offset

1,6

Links

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

Example

Maximal 8 X 8 example
.0.0.1.1.1.1.0.0
.0.0.0.1.1.0.0.0
.1.0.0.0.0.0.0.1
.1.1.0.0.0.0.1.1
.1.1.0.0.0.0.1.1
.1.0.0.0.0.0.0.1
.0.0.0.1.1.0.0.0
.0.0.1.1.1.1.0.0

Crossrefs

Sequence in context: A011948 A256216 A285462 * A219498 A358078 A219754

Adjacent sequences: A146384 A146385 A146386 * A146388 A146389 A146390

Keyword

nonn

Author

R. H. Hardin

Status

approved