Number of nX4 0..3 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 4, no adjacent elements equal, and upper left element zero.

A231059

Number of nX4 0..3 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 4, no adjacent elements equal, and upper left element zero.

Terms

    a(0) =0a(1) =20a(2) =208a(3) =2376a(4) =27346a(5) =313944a(6) =3607664a(7) =41448458a(8) =476228082a(9) =5471653976a(10) =62867030958a(11) =722316016670

External references