Number of nX2 0..3 arrays with exactly floor(nX2/2) elements unequal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..3 order.
A222660
Number of nX2 0..3 arrays with exactly 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) =0a(1) =0a(2) =2a(3) =9a(4) =26a(5) =103a(6) =446a(7) =1964a(8) =8624a(9) =38467a(10) =172996a(11) =781826a(12) =3543506a(13) =16101962a(14) =73319508a(15) =334431875a(16) =1527675428a(17) =6987461432a(18) =31997430636a(19) =146680198680a(20) =673052434686
External references
- oeis: A222660