A146907 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 0010-1110-0111-0100 pattern in any orientation.

1, 1, 1, 3, 1, 3, 1, 5, 7, 23, 21, 73, 67, 331, 379, 2159, 3073, 18347, 29787, 200555, 362821, 2889871, 5926103, 54516713, 129199873, 1351622999, 3735869433, 44518336027, 139642079573, 1907609753527

Offset

1,4

Links

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

Example

Maximal 8 X 8 example
.0.0.1.0.0.0.1.0
.1.1.1.0.1.1.1.0
.0.1.1.1.0.1.1.1
.0.1.0.0.0.1.0.0
.0.0.1.0.0.0.1.0
.1.1.1.0.1.1.1.0
.0.1.1.1.0.1.1.1
.0.1.0.0.0.1.0.0

Crossrefs

Sequence in context: A328573 A369066 A283461 * A322865 A238694 A320221

Adjacent sequences: A146904 A146905 A146906 * A146908 A146909 A146910

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved