Number of 2n X 2 0..4 arrays with values 0..4 introduced in row major order and each element equal to exactly one horizontal and vertical neighbor.

A198405

Number of 2n X 2 0..4 arrays with values 0..4 introduced in row major order and each element equal to exactly one horizontal and vertical neighbor.

Terms

    a(0) =2a(1) =17a(2) =377a(3) =11473a(4) =375273a(5) =12456897a(6) =414711897a(7) =13814539697a(8) =460231956937

External references