Number of nX4 0..4 arrays with each element equal to the number its horizontal and vertical zero neighbors.
A197050
Number of nX4 0..4 arrays with each element equal to the number its horizontal and vertical zero neighbors.
Terms
- a(0) =3a(1) =6a(2) =18a(3) =42a(4) =108a(5) =274a(6) =692a(7) =1754a(8) =4442a(9) =11248a(10) =28488a(11) =72146a(12) =182712a(13) =462728a(14) =1171876a(15) =2967826a(16) =7516146a(17) =19034954a(18) =48206826a(19) =122085820a(20) =309187486a(21) =783030352a(22) =1983057390a(23) =5022176478a(24) =12718873752a(25) =32211084212a(26) =81575929322a(27) =206594481604
External references
- oeis: A197050