Number of nX1 0..3 arrays with no more than floor(nX1/2) elements equal to at least one king-move neighbor, with new values introduced in row major 0..3 order.

A222650

Number of nX1 0..3 arrays with no more than floor(nX1/2) elements equal to at least one king-move neighbor, with new values introduced in row major 0..3 order.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =11a(4) =34a(5) =131a(6) =438a(7) =2150a(8) =7676a(9) =32491a(10) =116096a(11) =533186a(12) =1945184a(13) =8362152a(14) =30561808a(15) =135650378a(16) =501075616a(17) =2155759835a(18) =7986345032a(19) =34780282521a(20) =129686419290a(21) =555913562689

External references