A146597 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1000-1000-1111 pattern in any orientation.

1, 1, 1, 1, 3, 7, 19, 51, 237, 1335, 8829, 68891, 649429, 7839465, 116522409, 2129542541, 47609599737, 1308687213295, 44429361526611, 1853713445956347

Offset

1,5

Links

Table of n, a(n) for n=1..20.

Example

Maximal 8 X 8 example
.0.1.1.1.1.0.0.0
.1.0.0.0.1.0.0.0
.1.0.0.0.1.0.0.0
.1.0.0.0.0.1.1.1
.1.1.1.0.0.0.0.1
.0.0.0.1.0.0.0.1
.0.0.0.1.0.0.0.1
.0.0.0.1.1.1.1.0

Crossrefs

Sequence in context: A087432 A135052 A198305 * A320734 A259812 A115254

Adjacent sequences: A146594 A146595 A146596 * A146598 A146599 A146600

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved