Number of linear arrangements of n blue, n red and n green items such that first and last elements are blue but there are no adjacent items of the same color.
A141146
Number of linear arrangements of n blue, n red and n green items such that first and last elements are blue but there are no adjacent items of the same color.
Terms
- a(0) =0a(1) =2a(2) =14a(3) =96a(4) =664a(5) =4660a(6) =33144a(7) =238448a(8) =1732112a(9) =12685428a(10) =93552700a(11) =694072720a(12) =5176136640a(13) =38777105120a(14) =291661779920
External references
- oeis: A141146