A146834 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1001-1111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 5, 17, 41, 159, 789, 4693, 37959, 362149, 3798435, 51198703, 878343647, 18110228679, 463058495339, 14563433819389, 553118211838649, 25843199757659397

Offset

1,6

Links

Table of n, a(n) for n=1..21.

Example

Maximal 8 X 8 example
.0.0.1.0.0.1.0.0
.0.0.1.1.1.1.0.0
.1.1.0.1.0.0.1.1
.0.1.1.0.0.0.1.0
.0.1.0.0.0.1.1.0
.1.1.0.0.1.0.1.1
.0.0.1.1.1.1.0.0
.0.0.1.0.0.1.0.0

Crossrefs

Sequence in context: A201599 A246636 A146794 * A130739 A147412 A273116

Adjacent sequences: A146831 A146832 A146833 * A146835 A146836 A146837

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved