A146811 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1010-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 7, 15, 31, 65, 179, 483, 1549, 5893, 23203, 108809, 513209, 2742185, 15938025, 102500855

Offset

1,8

Links

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

Example

Maximal 8 X 8 example
.0.0.0.1.1.1.1.0
.0.0.0.1.0.1.0.1
.0.0.0.1.0.0.1.1
.1.1.1.0.0.0.0.1
.1.0.0.0.0.1.1.1
.1.1.0.0.1.0.0.0
.1.0.1.0.1.0.0.0
.0.1.1.1.1.0.0.0

Crossrefs

Sequence in context: A129984 A365530 A351707 * A147235 A024876 A146598

Adjacent sequences: A146808 A146809 A146810 * A146812 A146813 A146814

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved