Number of (n+1) X 4 0..3 arrays with every 2 X 2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor.

A206338

Number of (n+1) X 4 0..3 arrays with every 2 X 2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor.

Terms

    a(0) =455a(1) =232a(2) =1340a(3) =682a(4) =4007a(5) =2030a(6) =12005a(7) =6074a(8) =35999a(9) =18206a(10) =107983a(11) =54606a(12) =323937a(13) =163806a(14) =971799a(15) =491406a(16) =2915385a(17) =1474206a(18) =8746143a(19) =4422606a(20) =26238417a(21) =13267806a(22) =78715239a(23) =39803406a(24) =236145705a(25) =119410206a(26) =708437103a(27) =358230606a(28) =2125311297

External references