Half the number of n X n binary arrays with the number of 1-1 adjacencies equal to the number of 0-0 adjacencies.

A183248

Half the number of n X n binary arrays with the number of 1-1 adjacencies equal to the number of 0-0 adjacencies.

Terms

    a(0) =1a(1) =3a(2) =25a(3) =2101a(4) =807261a(5) =1333831052

External references