A146457 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-0111-0010 pattern in any orientation.

1, 1, 1, 1, 1, 1, 3, 5, 15, 27, 85, 213, 947, 2889, 18347, 72469, 534735, 2688781, 25770975, 165859999, 2076582639, 17137608411, 273236370839, 2882703759335, 58601499839763

Offset

1,7

Links

Table of n, a(n) for n=1..25.

Example

Maximal 8 X 8 example
.0.0.0.0.0.1.1.0
.0.0.0.1.1.1.0.1
.0.0.0.0.1.0.1.1
.0.1.0.0.0.1.1.0
.0.1.1.0.0.0.1.0
.1.1.0.1.0.0.0.0
.1.0.1.1.1.0.0.0
.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A290230 A274638 A146244 * A051044 A353765 A358584

Adjacent sequences: A146454 A146455 A146456 * A146458 A146459 A146460

Keyword

nonn

Author

R. H. Hardin

Status

approved