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

A222680

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

Terms

    a(0) =2a(1) =1a(2) =5a(3) =10a(4) =25a(5) =150a(6) =359a(7) =2249a(8) =6511a(9) =39991a(10) =119033a(11) =747758a(12) =2254819a(13) =14115927a(14) =43486517a(15) =268330409a(16) =844434635a(17) =5129191736a(18) =16468845241a(19) =98454511005a(20) =322307191185

External references