Number of nX2 0..2 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..2 order.

A222643

Number of nX2 0..2 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..2 order.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =12a(4) =38a(5) =124a(6) =430a(7) =1530a(8) =5378a(9) =18938a(10) =67042a(11) =238446a(12) =849586a(13) =3033214a(14) =10851386a(15) =38895414a(16) =139634834a(17) =502003486a(18) =1807104810a(19) =6512929766a(20) =23498319154a(21) =84864219966a(22) =306764487338

External references