Number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor.

A206337

Number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor.

Terms

    a(0) =96a(1) =181a(2) =232a(3) =534a(4) =686a(5) =1589a(6) =2042a(7) =4751a(8) =6110a(9) =14239a(10) =18318a(11) =42705a(12) =54942a(13) =128103a(14) =164814a(15) =384297a(16) =494430a(17) =1152879a(18) =1483278a(19) =3458625a(20) =4449822a(21) =10375863a(22) =13349454a(23) =31127577a(24) =40048350a(25) =93382719a(26) =120145038a(27) =280148145a(28) =360435102a(29) =840444423

External references