Number of 3Xn arrays containing n copies of 0..3-1 with no element plus any horizontal or vertical neighbor equal to 3-1.

A265664

Number of 3Xn arrays containing n copies of 0..3-1 with no element plus any horizontal or vertical neighbor equal to 3-1.

Terms

    a(0) =2a(1) =0a(2) =4a(3) =16a(4) =60a(5) =228a(6) =1024a(7) =4288a(8) =18172a(9) =76838a(10) =326264a(11) =1390048a(12) =5947760a(13) =25515274a(14) =109801760a(15) =473895774a(16) =2050771696a(17) =8896415264a(18) =38680996104a(19) =168532976250a(20) =735715851956

External references