Number of n X 3 1..2 arrays containing at least one of each value, and all equal values connected.

A166761

Number of n X 3 1..2 arrays containing at least one of each value, and all equal values connected.

Terms

    a(0) =4a(1) =30a(2) =106a(3) =292a(4) =712a(5) =1618a(6) =3518a(7) =7432a(8) =15404a(9) =31526a(10) =63986a(11) =129164a(12) =259824a(13) =521498a(14) =1045254a(15) =2093232a(16) =4189716a(17) =8383278a(18) =16771066a(19) =33547380a(20) =67100824a(21) =134208610a(22) =268425166a(23) =536859352a(24) =1073728892a(25) =2147469238a(26) =4294951298a(27) =8589916892

External references