Number of nX2 0..3 arrays with values 0..3 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

A199143

Number of nX2 0..3 arrays with values 0..3 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

Terms

    a(0) =1a(1) =3a(2) =13a(3) =65a(4) =393a(5) =2539a(6) =16866a(7) =113432a(8) =766473a(9) =5188597a(10) =35148945a(11) =238173743a(12) =1614066774a(13) =10938730576a(14) =74134306725a(15) =502428413393

External references