Number of (n+1)X7 0..3 arrays with every 2X2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor.

A206341

Number of (n+1)X7 0..3 arrays with every 2X2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor.

Terms

    a(0) =880a(1) =1589a(2) =2030a(3) =4711a(4) =6090a(5) =14181a(6) =18258a(7) =42351a(8) =54654a(9) =126861a(10) =163842a(11) =380391a(12) =491406a(13) =1141143a(14) =1474206a(15) =3423417a(16) =4422606a(17) =10270239a(18) =13267806a(19) =30810705a(20) =39803406a(21) =92432103a(22) =119410206a(23) =277296297a(24) =358230606a(25) =831888879a(26) =1074691806

External references