A146733 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1110-0111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 7, 21, 51, 221, 1241, 9517, 82699, 831417, 10562039, 171512909, 3474881423, 89012624955, 2811600551097, 108083175359051, 5158385898284233, 309138121525742883

Offset

1,6

Links

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

Example

Maximal 8 X 8 example
.0.0.0.1.1.1.0.0
.0.0.1.1.1.0.0.0
.0.1.0.0.1.0.0.1
.1.1.0.0.0.1.1.1
.1.1.1.0.0.0.1.1
.1.0.0.1.0.0.1.0
.0.0.0.1.1.1.0.0
.0.0.1.1.1.0.0.0

Crossrefs

Sequence in context: A083012 A233329 A070313 * A146709 A146400 A146408

Adjacent sequences: A146730 A146731 A146732 * A146734 A146735 A146736

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved