1/24 the number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock containing exactly three distinct values.
A183586
1/24 the number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock containing exactly three distinct values.
Terms
- a(0) =6a(1) =56a(2) =520a(3) =4832a(4) =44896a(5) =417152a(6) =3875968a(7) =36013568a(8) =334620160a(9) =3109124096a(10) =28888434688a(11) =268416966656
External references
- oeis: A183586