Number of (n+1)X6 0..3 arrays with every 2X2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor.

A206340

Number of (n+1)X6 0..3 arrays with every 2X2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor.

Terms

    a(0) =1376a(1) =686a(2) =4007a(3) =2034a(4) =12021a(5) =6090a(6) =36015a(7) =18222a(8) =107997a(9) =54618a(10) =323943a(11) =163806a(12) =971799a(13) =491406a(14) =2915385a(15) =1474206a(16) =8746143a(17) =4422606a(18) =26238417a(19) =13267806a(20) =78715239a(21) =39803406a(22) =236145705a(23) =119410206a(24) =708437103a(25) =358230606a(26) =2125311297

External references