A146282 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 111-110-111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 9, 5, 29, 17, 313, 37, 1657, 109, 19905, 2661, 319705, 46501, 11762329, 480069, 357135757, 5729689, 14191646903, 346242155, 884769592659, 24356919567

Offset

1,7

Links

Table of n, a(n) for n=1..26.

Example

Maximal 8 X 8 example
.1.0.1.0.0.1.0.1
.1.1.1.0.0.1.1.1
.1.1.1.0.0.1.1.1
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.1.1.1.0.0.1.1.1
.1.1.1.0.0.1.1.1
.1.0.1.0.0.1.0.1

Crossrefs

Sequence in context: A298584 A238475 A180878 * A117911 A061041 A248308

Adjacent sequences: A146279 A146280 A146281 * A146283 A146284 A146285

Keyword

nonn

Author

R. H. Hardin

Status

approved