A146260 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 110-111-101 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 5, 13, 25, 47, 113, 351, 1317, 5315, 24057, 110167, 558903, 3123765, 20513901, 147650027, 1233473669, 10827756731

Offset

1,8

Links

Table of n, a(n) for n=1..23.

Example

Maximal 8 X 8 example
.0.0.0.1.0.1.0.0
.0.0.0.1.1.1.0.0
.0.0.0.1.1.0.1.1
.1.1.1.0.0.1.1.0
.0.1.1.0.0.1.1.1
.1.1.0.1.1.0.0.0
.0.0.1.1.1.0.0.0
.0.0.1.0.1.0.0.0

Crossrefs

Sequence in context: A147182 A146175 A146851 * A147166 A146192 A147265

Adjacent sequences: A146257 A146258 A146259 * A146261 A146262 A146263

Keyword

nonn

Author

R. H. Hardin

Status

approved