Number of nX2 0..3 arrays with exactly floor(nX2/2) elements unequal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..3 order.
A222270
Number of nX2 0..3 arrays with exactly floor(nX2/2) elements unequal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..3 order.
Terms
- a(0) =0a(1) =0a(2) =4a(3) =13a(4) =40a(5) =162a(6) =888a(7) =3617a(8) =18136a(9) =81560a(10) =407644a(11) =1901375a(12) =9349056a(13) =44712494a(14) =218395880a(15) =1057844425a(16) =5154076928a(17) =25146813236a(18) =122532346416a(19) =600293886818
External references
- oeis: A222270