A146475 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1110-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 9, 15, 35, 57, 245, 579, 3057, 8465, 49975, 173815, 1305505, 5674409, 52338659, 276967501, 3125019047, 20455456921, 286529633207, 2318729204115

Offset

1,7

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.1.1.1.0
.1.0.0.1.1.1.0.0
.1.1.0.0.0.0.0.0
.1.1.0.0.0.0.1.0
.0.1.0.0.0.0.1.1
.0.0.0.0.0.0.1.1
.0.0.1.1.1.0.0.1
.0.1.1.1.0.0.0.0

Crossrefs

Sequence in context: A125216 A058505 A133763 * A307217 A100556 A057478

Adjacent sequences: A146472 A146473 A146474 * A146476 A146477 A146478

Keyword

nonn

Author

R. H. Hardin

Status

approved