1/24 the number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock containing exactly three distinct values.

A183587

1/24 the number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock containing exactly three distinct values.

Terms

    a(0) =56a(1) =1243a(2) =27380a(3) =603766a(4) =13311808a(5) =293504588a(6) =6471298096a(7) =142681644568

External references