A145935 Number of n X n binary arrays with all ones connected only in a 2X2 elbow 1,1 1,2 2,1 in any orientation.

1, 5, 19, 161, 4227, 156459, 12465353, 2072728127, 654619864141, 416229285287827, 526917547596105835, 1322031106068978041109, 6596380266620378636773707, 65393268733886793784592388811

Offset

1,2

Links

Table of n, a(n) for n=1..14.

Example

Maximal 8 X 8 example
.1.1.0.1.1.0.1.1
.1.0.0.0.1.0.0.1
.0.0.1.1.0.1.1.0
.1.1.0.1.0.1.0.0
.1.0.1.0.1.0.1.1
.0.1.1.0.1.1.0.1
.1.0.0.1.0.0.1.0
.1.1.0.1.1.0.1.1

Crossrefs

Sequence in context: A193287 A027269 A082790 * A024529 A363000 A106991

Adjacent sequences: A145932 A145933 A145934 * A145936 A145937 A145938

Keyword

nonn

Author

R. H. Hardin, Oct 25 2008

Status

approved