Number of nX4 0..1 arrays with every element unequal to 2 or 3 horizontally or vertically adjacent elements, with upper left element zero.

A303632

Number of nX4 0..1 arrays with every element unequal to 2 or 3 horizontally or vertically adjacent elements, with upper left element zero.

Terms

    a(0) =0a(1) =2a(2) =1a(3) =4a(4) =8a(5) =22a(6) =47a(7) =123a(8) =302a(9) =784a(10) =1961a(11) =5002a(12) =12715a(13) =32486a(14) =82753a(15) =211121a(16) =538371a(17) =1373975a(18) =3505385a(19) =8944576a(20) =22822438a(21) =58237614a(22) =148606194a(23) =379208575a(24) =967645940a(25) =2469221128a(26) =6300909758a(27) =16078584921a(28) =41029120473a(29) =104697723446

External references