A147408 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1001-1001-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 5, 13, 25, 49, 175, 865, 4191, 18461, 94551, 650857, 5436423, 49032533, 472638523, 5306220921, 72329183333, 1150334935553, 20498079126697, 410408073960755

Offset

1,7

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.0.0.0.0.1.0.0.1
.0.0.0.0.1.0.0.1
.0.0.0.0.1.1.1.1
.0.1.1.1.0.0.0.0
.0.0.0.1.0.0.0.0
.0.0.0.1.0.0.0.0
.0.1.1.1.0.0.0.0

Crossrefs

Sequence in context: A272705 A147272 A147427 * A241657 A249513 A147090

Adjacent sequences: A147405 A147406 A147407 * A147409 A147410 A147411

Keyword

nonn

Author

R. H. Hardin

Status

approved