A146377 - OEIS

A146377

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 0100-1111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 7, 13, 21, 39, 136, 493, 1722, 5497, 18675, 87521, 494306, 2893703, 17090719, 106149289, 783678982, 6830573137, 66084580709, 674363788779, 7402933526180, 90919163844646, 1283657951631942, 20222581811585561

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OFFSET

1,8

LINKS

Table of n, a(n) for n=1..30.

EXAMPLE

Maximal 8 X 8 example

.0.0.0.0.1.0.0.0

.0.0.1.1.1.1.0.0

.0.1.0.0.1.0.1.0

.0.1.0.0.0.1.1.1

.1.1.1.0.0.0.1.0