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

A207142

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

Terms

    a(0) =50a(1) =30a(2) =80a(3) =62a(4) =159a(5) =122a(6) =315a(7) =242a(8) =628a(9) =482a(10) =1254a(11) =962a(12) =2506a(13) =1922a(14) =5010a(15) =3842a(16) =10018a(17) =7682a(18) =20034a(19) =15362a(20) =40066a(21) =30722a(22) =80130a(23) =61442a(24) =160258a(25) =122882a(26) =320514a(27) =245762a(28) =641026a(29) =491522

External references