Number of nX2 0..3 arrays with no more than floor(nX2/2) elements unequal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..3 order.

A222610

Number of nX2 0..3 arrays with no more than floor(nX2/2) elements unequal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..3 order.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =12a(4) =40a(5) =149a(6) =615a(7) =2659a(8) =11641a(9) =51672a(10) =231598a(11) =1044550a(12) =4729221a(13) =21473854a(14) =97727797a(15) =445587611a(16) =2034814173a(17) =9304775285a(18) =42600153350a(19) =195249156987a(20) =895771869115

External references