A146441 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-0100-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 9, 19, 39, 119, 357, 921, 3063, 15421, 82217, 416323, 2370803, 16101191, 113312875, 843888839, 7373458463, 76576709025

Offset

1,8

Links

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

Example

Maximal 8 X 8 example
.0.1.1.1.0.0.0.0
.1.0.0.1.0.0.0.0
.1.0.0.1.1.0.0.0
.1.1.1.0.0.1.0.0
.0.0.1.0.0.1.1.1
.0.0.0.1.1.0.0.1
.0.0.0.0.1.0.0.1
.0.0.0.0.1.1.1.0

Crossrefs

Sequence in context: A327381 A146819 A147213 * A147341 A208972 A307541

Adjacent sequences: A146438 A146439 A146440 * A146442 A146443 A146444

Keyword

nonn

Author

R. H. Hardin

Status

approved