Number of (n+2) X 3 binary arrays with each 3 X 3 subblock having a positive determinant.

A186055

Number of (n+2) X 3 binary arrays with each 3 X 3 subblock having a positive determinant.

Terms

    a(0) =87a(1) =267a(2) =792a(3) =2328a(4) =6915a(5) =20475a(6) =60588a(7) =179442a(8) =531306a(9) =1573062a(10) =4657767a(11) =13791129a(12) =40833855a(13) =120904779a(14) =357985743a(15) =1059956097a(16) =3138413982a(17) =9292498818a(18) =27514066965a(19) =81466129305a(20) =241212255042a(21) =714202974702

External references