A145952 Number of n X n binary arrays with all ones connected only in a zee 1,1 1,2 2,2 2,3 in any orientation.

1, 1, 9, 33, 333, 7127, 205501, 11166945, 1122739259, 190153543115, 56969419979245, 30406497496961445, 28371939730808217655

Offset

1,3

Links

Table of n, a(n) for n=1..13.

Example

Maximal 8 X 8 example
.0.1.0.1.1.0.0.0
.1.1.0.0.1.1.0.0
.1.0.0.0.0.0.1.0
.0.1.0.1.1.0.1.1
.0.1.1.0.1.1.0.1
.0.0.1.0.0.0.1.0
.1.1.0.1.1.0.1.1
.0.1.1.0.1.1.0.1

Crossrefs

Sequence in context: A343843 A063423 A183939 * A172498 A276284 A275695

Adjacent sequences: A145949 A145950 A145951 * A145953 A145954 A145955

Keyword

nonn

Author

R. H. Hardin, Oct 25 2008

Status

approved