A147235 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1101-0111-0001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 7, 15, 31, 65, 185, 517, 1673, 6585, 26113, 126591, 608081, 3381041, 20245821, 136182387

Offset

1,8

Links

Table of n, a(n) for n=1..22.

Example

Maximal 8 X 8 example
.0.0.0.1.0.1.1.0
.0.0.0.1.1.1.0.1
.0.0.0.1.0.0.1.1
.1.1.1.0.0.0.1.0
.0.1.0.0.0.1.1.1
.1.1.0.0.1.0.0.0
.1.0.1.1.1.0.0.0
.0.1.1.0.1.0.0.0

Crossrefs

Sequence in context: A365530 A351707 A146811 * A024876 A146598 A147094

Adjacent sequences: A147232 A147233 A147234 * A147236 A147237 A147238

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved