Number of n X 2 0..2 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 3 and at least one element with value (x(i,j)-1) mod 3, and upper left element zero.
A230813
Number of n X 2 0..2 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 3 and at least one element with value (x(i,j)-1) mod 3, and upper left element zero.
Terms
- a(0) =0a(1) =0a(2) =2a(3) =0a(4) =2a(5) =12a(6) =18a(7) =56a(8) =170a(9) =420a(10) =1162a(11) =3200a(12) =8562a(13) =23292a(14) =63298a(15) =171336a(16) =464890a(17) =1261140a(18) =3419322a(19) =9274000a(20) =25152322a(21) =68211372a(22) =184993778a(23) =501712216a(24) =1360654410a(25) =3690150660a(26) =10007829482a(27) =27141578400a(28) =73608971282a(29) =199630236252
External references
- oeis: A230813