Number of permutations of n copies of 1..4 introduced in order 1..4 with no element equal to another within a distance of 2.
A190919
Number of permutations of n copies of 1..4 introduced in order 1..4 with no element equal to another within a distance of 2.
Terms
- a(0) =1a(1) =10a(2) =109a(3) =1277a(4) =15743a(5) =201562a(6) =2655555a(7) =35772051a(8) =490468025a(9) =6822301766a(10) =96037376333
External references
- oeis: A190919