Number of nX2 0..2 arrays with every element neighboring horizontally or vertically both a 0 and a 1.

A203536

Number of nX2 0..2 arrays with every element neighboring horizontally or vertically both a 0 and a 1.

Terms

    a(0) =0a(1) =4a(2) =4a(3) =16a(4) =64a(5) =196a(6) =676a(7) =2304a(8) =7744a(9) =26244a(10) =88804a(11) =300304a(12) =1016064a(13) =3437316a(14) =11628100a(15) =39337984a(16) =133079296a(17) =450203524a(18) =1523028676a(19) =5152368400a(20) =17430336576a(21) =58966408900a(22) =199481929956a(23) =674842534144

External references