T(n,k)=Number of 2nX2k 0..4 arrays with values 0..4 introduced in row major order and each element equal to exactly two horizontal and vertical neighbors.

A198253

T(n,k)=Number of 2nX2k 0..4 arrays with values 0..4 introduced in row major order and each element equal to exactly two horizontal and vertical neighbors.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =5a(5) =2a(6) =5a(7) =40a(8) =40a(9) =5a(10) =15a(11) =485a(12) =1675a(13) =485a(14) =15a(15) =51a(16) =6528a(17) =81440a(18) =81440a(19) =6528a(20) =51a(21) =187a(22) =90641a(23) =4059950a(24) =14520192a(25) =4059950a(26) =90641a(27) =187a(28) =715a(29) =1268648

External references