Number of nX3 0..2 arrays x(i,j) with each element horizontally, vertically or antidiagonally 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.

A231026

Number of nX3 0..2 arrays x(i,j) with each element horizontally, vertically or antidiagonally 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) =12a(2) =60a(3) =1074a(4) =12400a(5) =162288a(6) =2049324a(7) =26149710a(8) =332659424a(9) =4235875140a(10) =53922195170a(11) =686478044994

External references