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

A206335

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

Terms

    a(0) =192a(1) =181a(2) =1340a(3) =1581a(4) =12021a(5) =14181a(6) =108141a(7) =127581a(8) =973221a(9) =1148181a(10) =8758941a(11) =10333581a(12) =78830421a(13) =93002181a(14) =709473741a(15) =837019581a(16) =6385263621a(17) =7533176181a(18) =57467372541a(19) =67798585581a(20) =517206352821a(21) =610187270181

External references