1/6 the number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock containing all three values.

A183596

1/6 the number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock containing all three values.

Terms

    a(0) =27a(1) =204a(2) =1479a(3) =10797a(4) =78729a(5) =574185a(6) =4187499a(7) =30539367a(8) =222722937a(9) =1624313781a(10) =11846086563a(11) =86393262903a(12) =630064268913

External references