A147097 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1000-1000-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 13, 21, 45, 97, 227, 551, 1339, 4289, 13667, 51899, 209203, 857785, 3894865, 18769711, 98430017, 545007039

Offset

1,8

Links

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

Example

Maximal 8 X 8 example
.0.0.1.1.1.1.0.0
.0.0.1.0.0.0.0.0
.1.0.1.0.1.1.1.1
.1.0.1.0.0.0.0.1
.1.0.0.0.0.1.0.1
.1.1.1.1.0.1.0.1
.0.0.0.0.0.1.0.0
.0.0.1.1.1.1.0.0

Crossrefs

Sequence in context: A117766 A243162 A147351 * A147105 A258774 A057589

Adjacent sequences: A147094 A147095 A147096 * A147098 A147099 A147100

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved