A146859 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1101-0111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 5, 15, 25, 43, 109, 409, 1219, 6135, 18923, 91055, 376333, 2366771, 12618279, 101741365

Offset

1,8

Links

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

Example

Maximal 8 X 8 example
.0.0.1.0.1.1.0.0
.0.0.1.1.1.0.0.0
.1.1.0.0.1.0.0.1
.0.1.0.0.0.1.1.1
.1.1.1.0.0.0.1.0
.1.0.0.1.0.0.1.1
.0.0.0.1.1.1.0.0
.0.0.1.1.0.1.0.0

Crossrefs

Sequence in context: A018404 A053928 A146779 * A146835 A146795 A166479

Adjacent sequences: A146856 A146857 A146858 * A146860 A146861 A146862

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved